¶ 1. This case is before this court on certification from the court of appeals pursuant to Wis. Stat. § (Rule) 809.61 (2003-04).1 DaimlerChrysler appeals an order of the Circuit Court for Kenosha County, Honorable Wilbur W. Warren, Judge, affirming a worker's compensation decision of the Wisconsin Labor and Industry Review Commission (the LIRC). The LIRC determined that the defendant-respondent, Glenn May (May), was entitled to a minimum of 10 percent disability for each of two anterior cruciate ligament (ACL) repairs pursuant to Wis. Ad*10min. Code § DWD 80.32(4) (Sept., 2005)2, resulting in a 20 percent permanent partial disability (PPD) award.
¶ 2. We conclude that the LIRC's interpretations of Wis. Admin. Code § DWD 80.32(4) and Wis. Stat. § 102.18(l)(d) are entitled to controlling deference and great weight deference, respectively, and that the LIRC's award of 20 percent permanent partial disability to May should be upheld.
¶ 3. The certified question before this court is whether the LIRC may interpret Wis. Admin. Code § DWD 80.32(4) to award a cumulative minimum PPD for multiple ligament repair procedures, where the resulting award is higher than the highest medical estimate of PPD in evidence. We answer this question in the affirmative. We hold that § DWD 80.32(4) may be interpreted to award a cumulative minimum PPD for multiple ligament repair procedures, even though the award by the LIRC is higher than the highest medical estimate in the record. We further hold that Wis. Stat. § 102.18(l)(d) does not prohibit determinations in excess of the highest medical assessment in evidence, but rather creates a presumption of reasonableness for PPD awards that fall within the prescribed range. We therefore affirm the decision of the circuit court which affirmed the LIRC's award of 20 percent PPD to May.
I.
¶ 4. On April 19,1999, May, an employee of Daim-lerChrysler, was injured at work when an engine that he was carrying hit his left knee. The next day, May went to see Dr. Aftab Ansari, an orthopedic surgeon. May underwent ACL reconstruction surgery by Dr. *11Ansari on May 5, 1999. May continued to experience swelling, pain, and stiffness after the surgery. On April 24, 2001, Dr. Ansari examined May and noted atrophy to his left quadriceps. At that time, Dr. Ansari assessed 15 percent PPD of May's left knee.
¶ 5. On July 27, 2001, Dr. Ansari performed a second ACL reconstruction surgery. The second surgery improved May's knee substantially, and he returned to work in October 2001 without further problems. In April 2002 Dr. Ansari was given a copy of Wis. Admin. Code § DWD 80.32(4) and assessed the minimum 10 percent PPD of May's left knee. Doctor Ansari reported that May had reached a healing plateau, and further indicated that May's PPD had not changed due to the second ACL reconstruction. DaimlerChrysler paid May 10 percent PPD, which amounted to $7,820. May then filed a claim for additional compensation with the Department of Workforce Development (the DWD). Administrative Law Judge (ALJ) Sherman Mitchell awarded May 25 percent PPD, the amount determined by adding together Dr. Ansari's assessments from each of the two surgeries.
¶ 6. In reaching his conclusion, the ALJ applied Hellendrung v. WalMart, Claim No. 1999039147 (LIRC Feb. 23, 2001). In Hellendrung, the LIRC ruled that the note to Wis. Admin. Code § DWD 80.32(1) indicates that the same principles that are applied to surgical procedures to the back, also apply to surgical procedures to the knee, and that additional ratings and permanent disability will be given for cumulative surgeries. Id.
¶ 7. The worker's compensation applicant in Hellendrung had a long-standing history of knee problems prior to being injured at work. Following his work injury, the applicant sought treatment and underwent *12partial meniscectomy surgery. Id. The applicant's treating physician concluded that there was a causal relationship between the applicant's need for surgery and the work incident. Id. The ALJ awarded the applicant an additional 5 percent PPD of the knee. The employer argued in its petition to the LIRC for commission review that the language of Wis. Admin. Code § DWD 80.32(1) assumes that the member was previously without disability, and that appropriate reduction should have been made for any preexisting disability. However, the LIRC affirmed the ALJ and concluded in Hellendrung that a footnote to § DWD 80.32(1) indicates that the same principle that is applied to an award for surgical procedures to the hack is also applied in the case of procedures to the knee. Id. The LIRC concluded that § DWD 80.32(11) clearly contemplates that additional ratings and permanent disability will be given for cumulative surgeries to the back, and likewise to the knee, and that a reduction for any preexisting disability is most appropriately applied to previous losses of range of motion and amputations, but not to the surgical procedures listed in § DWD 80.32. Id.
¶ 8. In the present case, DaimlerChrysler petitioned the LIRC for review, alleging error by the ALJ. The LIRC affirmed in part and reversed in part, reaffirming its decision in Hellendrung, and concluding that the evidence did not establish that May was entitled to 25 percent PPD because Dr. Ansari stated, after the second ACL surgery, that May had regained full strength in his knee and had 10 percent PPD. The LIRC assessed 20 percent PPD to the knee, concluding that Wis. Admin. Code § DWD 80.32 provides a 10 percent minimum for an ACL reconstruction and that, because May underwent two ACL surgeries, he was entitled to a minimum 10 percent recovery for each knee surgery.
*13¶ 9. DaimlerChrysler then brought an action for judicial review under Wis. Stat. § 102.23. The Kenosha County Circuit Court, Judge Wilbur W. Warren, affirmed the LIRC's decision. DaimlerChrysler appealed, the court of appeals certified the matter to this court, and we accepted the certification.
II
¶ 10. Our analysis in this case focuses on the standard of review. In order to answer the certified question in this case, it is necessary for this court to interpret both an administrative rule, Wis. Admin. Code § DWD 80.32, especially Wis. Admin. Code § DWD 80.32(4), and a statute, Wis. Stat. § 102.18(l)(d). The application of an administrative rule and the application of a statute to undisputed facts are questions of law that we review de novo.3 Garcia v. Mazda Motor of Am., Inc., 2004 WI 93, 7, 273 Wis. 2d 612, 682 N.W.2d 365; Winters v. Winters, 2005 WI App 94, ¶ 7, 281 Wis. 2d 798, 699 N.W.2d 229. Further, when interpreting administrative regulations, we use the same rules of interpretation as we apply to statutes. State v. Busch, 217 Wis. 2d 429, 441, 576 N.W.2d 904 (1998) (citations omitted). When an administrative agency promulgates regulations pursuant to a power delegated by the legislature, we construe those regulations "together with the statute to make, if possible, an effectual piece of legislation in harmony with common sense and sound reason." Id.
¶ 11. Here, we review the decision of the LIRC. Brauneis v. LIRC, 2000 WI 69, ¶ 14, 236 Wis. 2d 27, *14612 N.W.2d 635. An administrative agency's interpretation of its own rules or regulations is controlling unless "plainly erroneous or inconsistent with the regulations." Busch, 217 Wis. 2d at 441 (citations omitted); see also RTE Corp. v. DILHR, 88 Wis. 2d 283, 290, 276 N.W.2d 290 (1979). Here, the LIRC reviewed a rule promulgated by the DWD, not the LIRC's own rule. The LIRC is an adjudicative body charged only with resolving certain disputes. Racine Harley-Davidson, Inc. v. State of Wis. Div. of Hearings and Appeals, 2006 WI 86, ¶ 35, 292 Wis. 2d 549, 717 N.W.2d 184. The LIRC is an independent agency of the State of Wisconsin and, although it is not an organizational subdivision of the DWD, it is " 'attached'" to the DWD for administrative purposes only.4 The LIRC does not make rules, except for rules governing its own procedures. Wis. Stat. § 103.04(2).
¶ 12. The LIRC was created for the purpose of reviewing claims issued by ALJs in three divisions of the DWD: Unemployment Insurance, Worker's Compensation, and Equal Rights.5 Pursuant to Wis. Stat. § 102.18(2)6, the DWD maintains on its staff ALJs to hear and decide disputed claims. When decisions of ALJs are appealed in each of the three DWD divisions, the LIRC reviews the evidence submitted at the hearing, considers the parties' arguments, consults with the *15ALJs if necessary, and then issues a written decision.7 The LIRC was charged by the legislature with the duty of reviewing the evidence and affirming, reversing, setting aside, or modifying those findings or orders, in whole or in part. Wis. Stat. § 102.18(3).
¶ 13. We conclude that the LIRC's interpretation of Wis. Admin. Code § DWD 80.32(4) is entitled to controlling weight deference, because the LIRC reasonably interpreted a rule adopted by the DWD, the LIRC's interpretation was not inconsistent with the language of the rule or clearly erroneous, and the LIRC was charged by the legislature with the duty of reviewing decisions issued by ALJs in the Worker's Compensation Division of the DWD, and does so frequently. Wis. Stat. § 102.18(3). See also RTE Corp., 88 Wis. 2d at 290.
¶ 14. Case law supports our decision to grant controlling deference to the LIRC in this case. In City of Elroy v. LIRC, 152 Wis. 2d 320, 324, 448 N.W.2d 438 (Ct. App. 1989), the court of appeals gave controlling weight deference to the LIRC's interpretation of a worker's compensation rule promulgated by the Industrial Commission8 under section Ind. 80.30 of the Wisconsin Administrative Code, since the interpretation was not inconsistent with the language of the rule or clearly erroneous. The court of appeals determined *16that the LIRC's conclusion was reasonable, and affirmed the LIRC's decision. Id. Similarly, in Hutchinson v. Custom Drywall, Inc., the court of appeals concluded that the LIRC's interpretation of Wis. Admin. Code § DWD 80.24 was entitled to controlling weight deference, because it was not inconsistent with the rule or clearly erroneous. Hutchinson v. Custom Drywall, Inc., No. 1997AP1675, unpublished slip op. (Wis. Ct. App. September 3, 1998)9.
¶ 15. Although the interpretation of a regulation and the interpretation of a statute are both questions of law, we determine the level of deference for agency statutory interpretations in a different manner. Hillhaven, 2000 WI App 20, ¶ 12 n.6, 232 Wis. 2d 400, 606 N.W.2d 572. An agency's statutory interpretations are generally accorded one of three levels of deference: great weight, due weight, or no deference. Id. However, for an agency's interpretation of its own rules or regulations, if the interpretation is reasonable and consistent with the intended purpose, we generally apply either "controlling weight" or "great weight" deference. Marder v. Bd. of Regents of the Univ. of Wis. Sys., 2004 WI App 177, ¶ 27 n.3, 276 Wis. 2d 186, 687 N.W.2d 832 (citing Hillhaven, 232 Wis. 2d 400, ¶ 12 n.6). However, "[d] espite the difference in terminology, the deference we give to an agency interpretation of its own rules is similar to the great weight standard applied to statutory interpretations." Marder, 276 Wis. 2d 186, ¶ 27 n.3. Both great weight deference and controlling weight deference "turn on whether the agency's interpretation *17is reasonable and consistent with the meaning or purpose of the regulation or statute." Id.
¶ 16. In order for an agency's interpretation of a statute to be accorded great weight deference, four requirements must be met: (1) the agency was charged by the legislature with the duty of administering the statute; (2) the interpretation of the agency is one of long-standing; (3) the agency employed its expertise or specialized knowledge in forming the interpretation; and (4) the agency's interpretation will provide uniformity in the application of the statute. Lisney v. LIRC, 171 Wis. 2d 499, 505, 493 N.W.2d 14 (1992); UFE Inc. v. LIRC, 201 Wis. 2d 274, 284, 548 N.W.2d 57 (1996). Under the standard of great weight deference, a court will refrain from substituting its view of the law for that of an agency charged with administration of the law, and will sustain the agency's conclusions of law if they are reasonable. Brown v. LIRC, 2003 WI 142, ¶ 19, 267 Wis. 2d 31, 671 N.W.2d 279. We will sustain an agency's conclusions of law even if an alternative view of the law is just as reasonable or even more reasonable. Id.
¶ 17. Due weight deference is appropriate when an agency has some experience in an area, but has not yet developed the expertise that would place it in a better position than a court to make judgments regarding the interpretation of the statute. UFE Inc., 201 Wis. 2d at 286. When applying due weight deference, we will not overturn a reasonable agency interpretation that is consistent with the purpose of the statute, unless there is a more reasonable interpretation. Hillhaven, 232 Wis. 2d 400, ¶ 12 n.6.
*18¶ 18. De novo review or no deference is appropriate where the issue is one of first impression, where the agency has no special expertise, or where the agency's position has been so inconsistent that it provides no real guidance. Am. Mfrs. Mut. Ins. Co. v. Hernandez, 2002 WI App 76, ¶ 14, 252 Wis. 2d 155, 642 N.W.2d 584.
¶ 19. The circuit court gave the LIRC's interpretation of Wis. Admin. Code § DWD 80.32 due deference, and noted that the court found no guidance in Wis. Stat. § 102.18(l)(d). For the following reasons, we conclude that the LIRC's interpretation of § 102.18(l)(d) is entitled to great weight deference, and that the LIRC's interpretation of § DWD 80.32(4) is entitled to controlling weight deference. As noted previously, controlling weight deference is similar to great weight deference, despite the difference in terminology, because both standards turn on whether the agency's interpretation is reasonable and consistent with the meaning or purpose of the regulation or statute. Marder, 276 Wis. 2d 186, ¶ 27 n.3. Controlling weight describes a level of deference given to an agency's interpretation and application of administrative rules and regulations, while great weight deference describes a level of deference given to an agency's interpretation and application of a statute.
¶ 20. The legislature empowered the DWD and the LIRC to administer the worker's compensation statutes. Beecher v. LIRC, 2004 WI 88, ¶ 25, 273 Wis. 2d 136, 682 N.W.2d 29. The LIRC employed its expertise and specialized knowledge in interpreting Wis. Stat. § 102.18(l)(d). The statute has been in effect for 26 years, and the LIRC has issued approximately 130 decisions on § 102.18(1) (d). See, e.g., Laughlin v. Tommy Bartlett, Inc., Claim Nos. 1999043589, 2002042491 (LIRC Aug. *1931, 2004); Greenwood v. Zurich Am. Ins. Co., Claim No. 1999046119 (LIRC Sept. 10, 2002). Finally, the LIRC has been consistent in its application of § 102.18(l)(d), such that its interpretation will provide uniformity in the application of the statute. Beecher, 273 Wis. 2d 136, ¶ 23. The LIRC has consistently declined to read § 102.18(1) (d) to mandate a range within which a PPD award must fall. Sconzert v. Bay Engineered Castings, Inc., Claim No. 2000011312 (LIRC June 28, 2001); Schouten v. Wis. Farmers Mut. Ins., Claim No. 89067604 (LIRC Mar. 10, 1994). Therefore, we accord the LIRC's interpretation of § 102.18(1)(d) great weight deference here, and we will sustain that interpretation, even if an alternative view of the law is just as reasonable or even more reasonable. Brown, 267 Wis. 2d 31, ¶ 19.
HH hH H — I
¶ 21. In its brief, the LIRC argues that this court lacks subject matter jurisdiction or competency, because the Joint Committee for Review of Administrative Rules (JCRAR) was never served with a copy of the petition for review. The LIRC argues that service upon the JCRAR is required by Wis. Stat. § 227.40(5)10. This issue is better characterized as one of competency, not one of subject matter jurisdiction. See Mueller v. Brunn, 105 Wis. 2d 171, 175-76, 313 N.W.2d 790 (1982);11 Currier v. DOR, *202006 WI App 12, ¶ 6 n.2, 288 Wis. 2d 693, 709 N.W.2d 520. Under the Wisconsin Constitution, circuit courts in Wisconsin have general original subject matter jurisdiction over "all matters civil and criminal." Wis. Const. art. VII, § 8; In re Eberhardy, 102 Wis. 2d 539, 550, 307 N.W.2d 881 (1981)(citations omitted). Here, the issue of competency to proceed was not raised before the circuit court, and we decline to disregard the resulting waiver. Under such circumstances, we need not address the issue of competency. Village of Trempealeau v. Mikrut, 2004 WI 79, ¶ 27, 273 Wis. 2d 76, 681 N.W.2d 190; see also Mut. Fed. Sav. Loan Ass'n of Milwaukee v. Sav. Loan Review Bd. of Wis., 46 Wis. 2d 110, 116, 174 N.W.2d 554 (1970), which involves the general rule that an issue not raised before the circuit court need not be addressed by an appellate court.
IV
¶ 22. We have concluded that the LIRC's interpretation of Wis. Admin. Code § DWD 80.32(4)12 is entitled to controlling weight deference. We will therefore uphold the agency's interpretation, unless such interpre*21tation is " 'inconsistent with the language of the regulation or clearly erroneous.'" Plevin v. DOT, 2003 WI App 211, ¶ 13, 267 Wis. 2d 281, 671 N.W.2d 355 (citation omitted). An administrative agency that regularly works with the rules and regulations of another agency, whose actions it is authorized by the legislature to *22review, is in the best position to interpret such rules and regulations because the agency knows the specific purposes of the rules and regulations that have been promulgated, and has expertise in the area the agency is called upon to review. Id.
¶ 23. As discussed earlier, the LIRC was established for the purpose of reviewing claims issued by ALJs in three divisions of the DWD: Unemployment Insurance, Worker's Compensation, and Equal Rights. The LIRC was "created to have final review authority of Department interpretations." DILHR v. LIRC, 161 Wis. 2d 231, 245, 467 N.W.2d 545 (1991). The LIRC corrects errors and "helps to assure consistent statutory application." Id.
¶ 24. DaimlerChrysIer argues that the LIRC's interpretation of Wis. Admin. Code § DWD 80.32(4) has been inconsistent, and therefore should be given no deference. To illustrate, DaimlerChrysIer notes that in Hellendrung, Claim No. 1999039147, and in the present case, the LIRC concluded that reductions for preexisting disabilities did not apply to the surgical procedures listed in Wis. Admin. Code § DWD 80.32. DaimlerChrysIer asserts that, in King v. DOT, Claim Nos. 2001007515 and 2003012619 (LIRC Apr. 27, 2005), the LIRC counted previous surgeries listed in § DWD 80.32 as preexisting disabilities that should be subtracted from the final PPD assessment.
¶ 25. We disagree with DaimlerChrysler's assertion that the LIRC's interpretation of Wis. Admin. Code § DWD 80.32 has been inconsistent. King is distinguishable from the present case because, in King, a second knee surgery was necessary because the applicant suffered from a second injury. The LIRC therefore reduced the disability determination for a preexisting *23condition. Id. In the present case, May did not suffer a second knee injury, but rather had an unsuccessful first surgery. The LIRC therefore made no reduction for a preexisting condition, since May did not have such a condition. The LIRC's decision in this case is consistent with its decision in Hall v. Consol. Thermoplastics, Claim No. 1995022808 (LIRC Sept. 29, 1999). In Hall, the LIRC made it clear that, where a surgery is performed "to cure and relieve the effects of the same work injury[,]" the LIRC will not make a reduction in the amount awarded for post-injury surgeries by subtracting the minimum assessment for one surgery from a later surgery. Id. The LIRC's decision in this case is also supported by its conclusion in Hellendrung, Claim No: 1999039147, that a reduction under Wis. Admin. Code § DWD 80.32(1) is appropriate for previous losses of range of motion and amputations, but not for the surgical procedures listed in § DWD 80.32.
¶ 26. The language of Wis. Admin. Code § DWD 80.32 does not specify how repeat ligament repair procedures should be treated. Wisconsin Admin. Code § DWD 80.32(1) states that the minimum disability percentages are "[t]he minimums for the described conditions," and that additional disabling elements may result in an award higher than the listed minimum. The minimum specified in Wis. Admin. Code § DWD 80.32(4) for an ACL repair to the knee is 10 percent.
¶ 27. The LIRC notes that Wis. Admin. Code § DWD 80.32(4) uses substantially identical language and format to set forth the minimum percentage for loss of use following an ACL procedure in the knee as Wis. Admin. Code § DWD 80.32(11) uses to set forth the minimum percentages following a procedure for removal of disc material or fusion in the spine. Both *24subsections describe the surgical procedure and then indicate the minimum loss of use rating.
¶ 28. Relying on Wilson v. Waukesha County, 157 Wis. 2d 790, 796, 460 N.W.2d 830 (Ct. App. 1990), the LIRC asserts that when substantially identical language is used in two subsections of the same administrative rule, the LIRC may consider an explanatory note discussing the meaning of language as used in one subsection, in order to interpret the language in the other subsection. In Wilson, the court of appeals used bill drafting records that discussed the meaning of a word in one subsection, in order to determine the meaning of the same word in another subsection of the same statute. Id. The LIRC asserts that it was reasonable to consider the note appended to Wis. Admin. Code § DWD 80.32(11) as being supportive of its interpretation of Wis. Admin. Code § DWD 80.32(4). Daimler-Chrysler asserts that the note to § DWD 80.32(11) applies only to that subsection, and that the DWD intended to give special effect to back procedures, and to exclude knee procedures.
¶ 29. To adopt DaimlerChrysler's argument would be to give different meanings to the same words within the same administrative rule. See Gen. Castings Corp. v. Winstead, 156 Wis. 2d 752, 759, 457 N.W.2d 557 (Ct. App. 1990) ("We reject an interpretation which ascribes different meanings to the same word as it variously appears in a statute unless the context clearly requires such an approach."). It is a basic rule of construction that we attribute the same definition to a word both times it is used in the same statute or administrative rule. Harnischfeger Corp. v. LIRC, 196 Wis. 2d 650, 663, 539 N.W.2d 98 (1995).
*25¶ 30. The text of Wis. Admin. Code §§ DWD 80.32(4) and (11) contains substantially similar wording. Absent any direction clearly requiring the LIRC to give different meanings to the same words, the LIRC did not err in concluding that the text of §§ DWD 80.32(4) and (11) should be interpreted in the same way. See Gen. Castings Corp., 156 Wis. 2d at 759. Nor was it error, in light of Wilson, 157 Wis. 2d at 796, for the LIRC to conclude that, just as additional minimum PPD percentages are allowable for repeat surgical spinal procedures, additional minimum PPD percentages are allowable for repeat surgical procedures to the knee.13
*26¶ 31. DaimlerChrysler goes on to assert that there cannot be an award for both of May's ACL surgeries because Wis. Admin. Code § DWD 80.32(1) requires reduction for preexisting disabilities. As we noted previously, Hellendrung, Claim No. 1999039147, is instructive on this point. In Hellendrung, the LIRC determined that a reduction under § 80.32(1) is appropriate for previous losses of range of motion and amputations, but not for the surgical procedures listed in Wis. Admin. Code § DWD 80.32. Anterior cruciate ligament reconstruction is one of the procedures listed in Wis. Admin. Code § DWD 80.32(4) and the LIRC's decision not to make a reduction for preexisting disability was, therefore, reasonable and consistent with the intended purpose. There was no preexisting disability or condition that predated May's original injury at work in April 1999.
¶ 32. Moreover, the preamble of Wis. Admin. Code § DWD 80.32 provides for "[m]inimum percentages of loss of use for amputation levels, losses of motion, sensory losses and surgical procedures." Statutes should be interpreted so that every word is given effect. Donaldson v. State, 93 Wis. 2d 306, 315, 286 N.W.2d 817 (1980). We construe administrative rules in the same manner as statutes. Baierl v. McTaggart, 2001 WI 107, ¶ 21, 245 Wis. 2d 632, 629 N.W.2d 277. The plural usage of "surgical procedures" in the preamble of § DWD 80.32 supports a conclusion that multiple or repeat surgical procedures are contemplated by the administrative rule.14
*27¶ 33. It is not necessary for this court to address DaimlerChrysler's hypothetical assertion that the LIRC's interpretation of Wis. Admin. Code § DWD 80.32(4) may lead to awards greater than 100 percent PPD. Worker's compensation cases are fact-intensive and, for this reason, we need not deal "with any of the hypothetical situations posed by the appellants." Town of Russell Volunteer Fire Dept. v. LIRC, 223 Wis. 2d 723, 738, 589 N.W.2d 445 (Ct. App. 1998). However, we are cognizant of the case of Blau v. Pecks Feed & Grain, Inc., Claim No. 1988015510 (LIRC July 19, 2001), in which the LIRC applied Wis. Stat. § 102.44(4),15 and, based on that statute, determined that an employee may not be awarded PPD in excess of 100 percent.
*28V
¶ 34. As noted previously, where great weight deference is given to the LÍRC's interpretation and application of a statute such as Wis. Stat. § I02.l8(l)(d),16 this court will not substitute its view of the law for that of the LIRC, and will sustain the agency's conclusions of law if they are reasonable. Brown, 267 Wis. 2d 31, ¶ 19.
¶ 35. DaimlerChrysler asserts that the LIRC erred in awarding May 20 percent PPD because Wis. Stat. § 102.18(l)(d) prohibits determinations in excess of the highest medical assessment in the record. Daim-lerChrysler further asserts that the LIRC's interpretation of Wis. Admin. Code § DWD 80.32(4) contravenes the language of § 102.18(1) (d). DaimlerChrysler asserts that § 102.18(l)(d) refers to an estimate of PPD that is "made by a practitioner which is in evidence" and that the statute specifically prohibits the LIRC from awarding PPD higher than the highest or lower than the lowest estimate in evidence. We disagree with DaimlerChrysler's argument that the LIRC's interpretation of § DWD 80.32(4) is inconsistent with § 102.18(l)(d).
¶ 36. Wisconsin Stat. § 102.18(l)(d) does not prohibit deviation from the range specified. Rather, § 102.18(l)(d) states clearly that any award within the *29range prescribed by the statute is "presumed to be a reasonable award. . . The statute does not state that an award outside of the prescribed range is unreasonable. Furthermore, § 102.18(l)(d) does not prohibit the DWD from setting minimum loss of use percentages by administrative rule. Administrative rules must be construed to be harmonious with statutory law dealing with the same subject matter, if it is feasible. Sommerfield v. Sommerfield, 154 Wis. 2d 840, 847, 454 N.W.2d 55 (Ct. App. 1990).
¶ 37. As noted previously, Wis. Stat. § 102.18(l)(d) provides in relevant part:
Any award which falls within a range of 5% of the highest or lowest estimate of permanent partial disability made by a practitioner which is in evidence is presumed to be a reasonable award, provided it is not higher than the highest or lower than the lowest estimate in evidence.
The first step of statutory interpretation is to look at the language of the statute; if the plain meaning is clear, a court need not look to the rules of statutory construction or to extrinsic sources of interpretation. UFE Inc., 201 Wis. 2d at 281. We assume that the legislature's intent is expressed in the statutory language. State ex rel. Kalal v. Circuit Court for Dane County, 2004 WI 58, ¶ 44, 271 Wis. 2d 633, 681 N.W.2d 110.
¶ 38. DaimlerChrysler, the LIRC, and May all took the position, in their respective briefs and at oral argument, that the language of Wis. Stat. § 102.18(l)(d) is clear and unambiguous. We agree, and therefore we need not resort to extrinsic sources such as legislative history; we simply apply the language of an unambigu*30ous statute to the facts before us. Bosco v. LIRC, 2004 WI 77, ¶ 24, 272 Wis. 2d 586, 681 N.W.2d 157 (citing Bruno v. Milwaukee County, 2003 WI 28, ¶ 20, 260 Wis. 2d 663, 660 N.W.2d 656). A statute is not ambiguous merely because the parties disagree as to its meaning, as they do here. Id., ¶ 7.
¶ 39. Wisconsin Stat., ch. 102, expressly recognizes PPD awards based on percentages set forth by the DWD. Wisconsin Stat. § 102.32(6)(b) states that "permanent disability can be determined based on a minimum permanent disability rating promulgated by the department by rule.. .." For the reasons stated herein, we conclude that the LIRC's interpretation of Wis. Stat. § 102.18(1)(d) is reasonable. As noted previously, in order for the LIRC's interpretation of § 102.18(l)(d) to be accorded great weight deference, four requirements must be met: (1) the agency was charged by the legislature with the duty of administering the statute; (2) the interpretation of the agency is one of longstanding; (3) the agency employed its expertise or specialized knowledge in forming the interpretation; and (4) the agency's interpretation will provide uniformity in the application of the statute. UFE Inc., 201 Wis. 2d at 284. Since all four requirements have been met here, we will sustain the LIRC's interpretation of § 102.18(l)(d) even if an alternative view is just as reasonable or more reasonable. Brown, 267 Wis. 2d 31, ¶ 19.
¶ 40. Relying on Pfister & Vogel Tanning Co. v. DILHR, 86 Wis. 2d 522, 273 N.W.2d 293 (1979), DaimlerChrysler further argues that there is no credible evidence in the record to support a 20 percent PPD award to May. In Pfister, physicians estimated that the plaintiff suffered either a 5 percent or a 15 percent *31disability, and DILHR made a 20 percent disability award. Id. This court reversed the circuit court's affir-mance of the award, holding that the award was not based upon credible evidence, and that there was error since the impairment of earning capacity had not been considered. Id. at 524,530-31. The percentages listed in Wis. Admin. Code § DWD 80.32 set the minimum loss of use percentage that may be awarded for each listed procedure, regardless of whether there is a doctor's estimated PPD in evidence. The minimum percentages are the product of a survey of practitioners with expertise in treating persons who have undergone the listed procedures, and of practitioners with expertise in assessing permanent partial disability.
¶ 41. However, Pfister was decided in 1978, while Wis. Stat. § 102.18(l)(d) was not enacted until 1980. Pfister was not decided based upon the current statute, and it never discussed the issue of the minimum PPDs set forth in Wis. Admin. Code § DWD 80.32. Pfister, therefore, is neither helpful nor instructive in regard to the circumstances presented here.
¶ 42. The LIRC's interpretation of Wis. Stat. § 102.18(l)(d) is reasonable. Since we accord great weight deference here, we affirm the LIRC's interpretation and application of § 102.18(l)(d) in this case.
VI
¶ 43. In summary, we conclude that the LIRC's interpretations of Wis. Admin. Code § DWD 80.32(4) and Wis. Stat. § 102.18(l)(d) are entitled to— controlling deference and great weight deference, respectively, and that the LIRC's award of 20 percent permanent partial disability to May should be upheld.
¶ 44. The certified question before this court is whether the LIRC may interpret Wis. Admin. Code *32§ DWD 80.32(4) to award a cumulative minimum PPD for multiple ligament repair procedures, where the resulting award is higher than the highest medical estimate of PPD in evidence. We answer this question in the affirmative. We hold that § DWD 80.32(4) may be interpreted to award a cumulative minimum PPD for multiple ligament repair procedures, even though the award by the LIRC is higher than the highest medical estimate in the record. We further hold that Wis. Stat. § 102.18(l)(d) does not prohibit determinations in excess of the highest medical assessment in evidence, but rather creates a presumption of reasonableness for PPD awards that fall within the prescribed range. We therefore affirm the decision of the circuit court, which affirmed the LIRC's award of 20 percent PPD to May.
By the Court. — The order of the circuit court is affirmed.
Wisconsin Stat. § (Rule) 809.61 provides in relevant part: "The supreme court may take jurisdiction of an appeal or other proceeding in the court of appeals upon certification by the court of appeals or upon the supreme court's own motion."
All references to the Wisconsin Statutes are to the 2003-04 version unless otherwise noted.
All references to the Wisconsin Administrative Code are to the September 2005 register date unless otherwise noted.
The parties do not dispute the facts in this case.
A Brief History of LIRC, http://www.dwd.state.wi.us/ lirc/lrc_about.htm (2006)
Id.
Wisconsin Stat. § 102.18(2) provides in relevant part, "The department shall have and maintain on its staff such examiners as are necessary to hear and decide disputed claims and to assist in the effective administration of this chapter. These examiners shall be attorneys and may be designated as administrative law judges."
A Brief History of LIRC, http://www.dwd.state.wi.us/ lirc/lrc_about.htm (2006)
The Industrial Commission was a predecessor agency to the DWD. In 1967, The Department of Industry, Labor, & Human Relations (the DILHR) was created from the former Industrial Commission. In 1996, the DWD replaced the DILHR as part of a major departmental reorganization. See DWD History, http://www.dwd.state.wi.us/dwd/DWDHistory/default. htm (2006).
We include an unpublished decision merely to show that controlling weight deference is regularly given to the LIRC's interpretation of the DWD's administrative rules.
Wisconsin Stat. § 227.40(5) provides in relevant part: "The joint committee for review of administrative rules shall be served with a copy of the petition in any action under this section and, with the approval of the joint committee on legislative organization, shall he made a party and be entitled to be heard."
Mueller v. Brunn, 105 Wis. 2d 171, 313 N.W.2d 790 (1982), was clarified in Village of Trempealeau v. Mikrut, 2004 WI 79, *20¶ 29, 273 Wis. 2d 76, 681 N.W.2d 190, which held that a challenge to a circuit court's competency should be raised before the circuit court in order to be preserved for appellate review. In Village of Trempealeau, we stated,
[T]he common-law waiver rule applies to challenges to the circuit court's competency, such that a challenge to the court's competency will be deemed waived if not raised in the circuit court, subject to the inherent authority of the reviewing court to disregard the wavier and address the merits of the unpreserved argument....
Id., ¶ 27.
Wisconsin Admin. Code § DWD 80.32 provides in relevant part:
*21(1) The disabilities set forth in this section are the mínimums for the described conditions. However, findings of additional disabling elements shall result in an estimate higher than the minimum. The minimum also assumes that the member, the back, etc., was previously without disability. Appropriate reduction shall be made for any pre-existing disability.
Note: An example would be where in addition to a described loss of motion, pain and circulatory disturbance further limits the use of an arm or a leg. A meniscectomy in a knee with less than a good result would call for an estimate higher than 5% loss of use of the leg at the knee. The same principle would apply to surgical procedures on the back. The schedule of minimum disabilities contained in this section was adopted upon the advice of a worker's compensation advisory council subcommittee after a survey of doctors experienced in treating industrial injuries.
(4) Knee
Anterior cruciate ligament repair 10%
(11) Back
Note: It is the subcommittee's intention that a separate minimum 5% allowance be given for every surgical procedure (open or closed, radical or partial) that is done to relieve from the effects of a disc lesion or spinal cord pressure. Each disc treated or surgical procedure performed will qualify for a 5% rating. Due to the fact a fusion involves 2 procedures a 1) laminectomy (dissectomy) and a 2) fusion procedure, 10% permanent total disability will apply when the 2 surgical procedures are done at the same time or separately.
The dissent, in ¶¶ 61-62, claims that the LIRC's decision is inconsistent with the intent of the Worker's Compensation Advisory Council Subcommittee (subcommittee). Notes to Wis. Admin. Code §§ DWD 80.32(1) and (11), resulting from the work of the subcommittee, show that the subcommittee intended to allow at least additional minimum PPD percentages to be applied for repeat or multiple surgical procedures. With respect to surgical procedures to the back, the note to § DWD 80.32(11) states in relevant part: "It is the subcommittee's intention that a separate minimum 5% allowance be given for every surgical procedure . . . that is done to relieve from the effects of a disc lesion or spinal cord pressure." As the LIRC points out in its brief, a note to § DWD 80.32(1) states in relevant part: "A meniscectomy in a knee with less than a good result would call for an estimate higher than [the. minimum in the code for a meniscectomy with excellent to good results]. The same principle would apply to surgical procedures on the back." These two notes, reflecting the intention of the subcommittee, strongly support the conclusion that the administrative rule was intended to be applied uniformly, regardless of whether the surgical procedure was to the knee, the hack, or another part of the body, and that the subcommittee intended that at least additional minimum PPD percentages be allowed for repeat or multiple surgical procedures for the same work injury.
Contrary to the position taken in ¶ 45 of the dissent, the LIRC's conclusion that additional minimum PPD percentages are allowable for repeat surgical procedures to the knee is an *27entirely reasonable one. The LIRC's decision contains a reasoned analysis that is consistent with the language of Wis. Admin. Code § DWD 80.32, the notes resulting from the work of the subcommittee, and the policy concerns underlying Wisconsin's Worker's Compensation Act. The LIRC's decision recognizes that repeat or multiple surgeries have a cumulative, negative effect on function of the body part upon which they are performed. The LIRC's decision is also consistent with the well-established principle "that the Worker's Compensation Act, ch. 102, Stats., is to be liberally construed to effectuate its goal of compensating and making injured workers whole...." ITW Deltar v. LIRC, 226 Wis. 2d 11, 18, 593 N.W.2d 908 (Ct. App. 1999).
Wisconsin Stat. § 102.44(4) provides in relevant part: "Where the permanent partial disability is covered by Wis. Stat. § 102.52, 102.53 and 102.55, such sections shall govern; provided, that in no case shall the percentage of permanent total disability be taken as more than 100 percent."
The assessment of disability to the extremities, such as the knee, is regulated by Wis. Stat. § 102.52, which determines percentages of disability based upon the maximum number of weeks allocated by the legislature for the injured body part.
Wisconsin Stat. § 102.18(l)(d) provides in relevant part:
Any award which falls within a range of 5% of the highest or lowest estimate of permanent partial disability made by a practitioner which is in evidence is presumed to be a reasonable award, provided it is not higher than the highest or lower than the lowest estimate in evidence.