The issue in this appeal from the workers’ compensation review board (board) concerns the proper method of calculating the cost-of-living adjustments (COLAs) of the plaintiff, Karyn Gil, whose injury occurred prior to October 1, 1991, and whose workers’ compensation benefits extend beyond October 1,1991, the effective date of Public Acts 1991, No. 91-*678339, § 27 (P.A. 91-339), which amended General Statutes § 31-307a (a).1 The defendant, the second injury fund (fund), appealed to the Appellate Court2 from a decision of the board, which reversed a finding and award of the workers’ compensation commissioner for the sixth district. We transferred the appeal to this court pursuant to Practice Book § 4023 and General Statutes § 51-199 (c). We reverse the judgment of the board and remand the case for further proceedings.
The relevant facts are as follows. On December 1, 1983, the plaintiff was exposed to chlorine gas during the course of her employment. As a result, she suffered *679permanent injury to her respiratory system. At the time of the accident, the plaintiff earned an average weekly wage of $139.96; her base compensation rate3 was $93.35. The fund assumed liability for the plaintiffs claim in November, 1986. The plaintiff has received total incapacity benefits from the date of her injury to the present, and in accordance with § 31-307a (a), she has received COLAs that have been added to her base compensation rate each October l.4
In 1991, the legislature enacted P.A. 91-339, § 27, amending § 31-307a (a). Prior to the enactment of P.A. 91-339, § 27, COLAs were calculated annually on October 1 by means of a flat dollar adjustment equal to the flat dollar increase in the maximum compensation rate from year to year.5 Public Act 91-339, § 27, altered the method by which COLAs were calculated, replacing the flat dollar adjustment method with a percentage adjustment method.6
*680In order to allay confusion caused by the new method of calculating COLAs, the then workers’ compensation commission chairman, John Arcudi, on October 30, 1991, promulgated an interpretation of P.A. 91-339, § 27 (Arcudi method). Arcudi interpreted § 27 to mandate percentage adjustments, rather than flat dollar adjustments, for all total disability claimants, including the plaintiff, on and after October 1, 1991. COLAs, under the Arcudi method, were calculated by multiplying the percentage increase each year of the maximum compensation rate by the claimant’s current adjusted compensation rate. Consequently, the claimant’s new adjusted compensation rate was comprised of that year’s COLA added to the previous year’s adjusted compensation rate.
Workers’ compensation payors followed Arcudi’s interpretation until June 5,1995, when the board issued its decision in Wolfe v. JAB Enterprises, Inc., 14 Conn. Workers’ Comp. Rev. Op. 127 (1995). In Wolfe, the board concluded that “[b]y its plain language, the statute [P.A. 91-339, § 27] increases the base compensation rate at the time of the injury by the percentage of the increase in the maximum compensation rate. The statutory formula does not contemplate an increase based in part on prior COLAs, as those take place [after] the time of the injury. This language is unambiguous, and we do not have discretion to construe it otherwise.” Id., 128.
Pursuant to the Wolfe decision, COLAs were calculated by determining the percentage increase between the maximum compensation rate at the time of injury and the current maximum compensation rate, multiplying that percentage by a claimant’s base compensation rate, and adding that amount to the base *681compensation rate. The fund altered its method for calculating annual COLAs to comply with the Wolfe decision and began implementing the new procedure in December, 1995. Under the Wolfe method of calculating COLAs, the plaintiffs biweekly check was reduced from $518.21 to $316.04. The plaintiff challenged the reduction in her benefits and was given a formal hearing before the sixth district commissioner on February 15, 1996. After the hearing, the commissioner rendered a decision ordering the fund to “reinstate the flat dollar amount of cost of living adjustments the claimant is entitled to receive through September 30,1991 and . . . only apply the formula for calculating adjustments on a percentage increase from October 1, 1991 forward in accordance with the statutory changes made by the enactment of P.A. 91-339.”
The fund subsequently petitioned the board for a review of the commissioner’s decision. Upon review, the board found that the amendments to § 31-307a (a) in P.A. 91-339, § 27, constituted “a change in the substance of our workers’ compensation law and therefore should not be applied retroactively.” The board then remanded the matter to the commissioner to enter an order in accordance with its determination that COLAs are to be calculated in accordance with the method of calculation in existence at the time of the injury. That method, in the case of the plaintiff, was the flat dollar COLA in effect prior to the effective date of P.A. 91-339. The fund appealed the board’s decision to the Appellate Court, and we transferred the appeal to this court pursuant to Practice Book § 4023 and General Statutes § 51-199 (c).
The fund urges us to adopt the Arcudi method of calculating COLAs as the proper application of the statute. Alternatively, the fund argues that the court should adopt the position of the board in Wolfe. The plaintiff would have us embrace the position taken by the board *682in this case and preserve the flat dollar COLA for those persons injured prior to the effective date of P.A. 91-339, applying a percentage formula only to those injured after that date. The Connecticut Business and Industry Association, an amicus curiae in this appeal, argues for a method of calculation that preserves the plaintiffs flat dollar COLAs to 1990, but applies the amended statute’s percentage rate to the plaintiff as of October 1, 1991.
This is a case of statutory construction and, as such, “[o]ur analysis of the plaintiffs claims is guided by well established tenets .... [0]ur fundamental objective is to ascertain and give effect to the apparent intent of the legislature. . . . In seeking to discern that intent, we look to the words of the statute itself, to the legislative history and circumstances surrounding its enactment, to the legislative policy it was designed to implement, and to its relationship to existing legislation and common law principles governing the same general subject matter.” (Internal quotation marks omitted.) M. DeMatteo Construction Co. v. New London, 236 Conn. 710, 714-15, 674 A.2d 845 (1996); see Metropolitan District Commission v. AFSCME, Council 4, Local 184, 237 Conn. 114, 120, 676 A.2d 825 (1996); State v. Burns, 236 Conn. 18, 22-23, 670 A.2d 851 (1996); State v. Spears, 234 Conn. 78, 86-87, 662 A.2d 80, cert. denied, 516 U.S. 1009, 116 S. Ct. 565, 133 L. Ed. 2d 490 (1995).
We acknowledge, however, that the Workers’ Compensation Act is remedial and must be interpreted liberally to achieve its humanitarian purposes. Weinberg v. ARA Vending Co., 223 Conn. 336, 341, 612 A.2d 1203 (1992); Dubois v. General Dynamics Corp., 222 Conn. 62, 67, 607 A.2d 431 (1992); Hansen v. Gordon, 221 Conn. 29, 32, 602 A.2d 560 (1992); Ash v. New Milford, 207 Conn. 665, 672, 541 A.2d 1233 (1988). “Because the [Workers’ Compensation Act] is a remedial statute, this court should not impose limitations on the benefits *683provided for a disabled worker that the statute itself does not clearly specify.” Misenti v. International Silver Co., 215 Conn. 206, 210, 575 A.2d 690 (1990).
If we were to restrict our view of the question at issue to a literal application of § 27 of P.A. 91-339, the resulting method of calculation of COLAs would be the alternate position espoused by the fund and the method set forth in the board’s decision in Wolfe. Basically, that method would have the current adjusted compensation rate determined by dividing the current maximum compensation rate by the maximum compensation rate on the date of the plaintiffs injury to find the percentage increase of the maximum compensation rate, and then multiplying that percentage increase by the plaintiffs base compensation rate.7 The increase over the plaintiffs base compensation rate would be the COLA for the current year. This application of the statute disregards the previous flat dollar COLAs and, as noted above, reduced the plaintiffs biweekly check from $518.21 to $316.04.
In addition to § 27, however, the legislature also enacted P.A. 91-339, § 50, to take effect October 1,1991, which provides: “Nothing in this act shall be construed to affect any claims for compensation arising from any injury that occurred before October 1, 1991. Nothing in this act shall be construed to reduce the amount of any compensation awarded for any injury that occurred before October 1,1991.” While the first sentence of § 50 concerns claims that were pending at the time the act *684was passed, the second sentence focuses on compensation and prohibits its reduction for those receiving compensation who were injured before October 1,1991.8 The intent of the legislature, as expressed in § 50, calls into question a literal application of § 27 because the legislature clearly did not intend to reduce benefits being received by persons injured prior to October 1,1991.
Representative Joseph A. Adamo, on the floor of the House of Representatives, expressed the legislature’s intent to safeguard the increased compensation received by claimants due to previous COLAs when he summarized P.A. 91-339. He said, in part, “[P.A. 91-339] goes on to repeal a number of sections under the act that are changed by this particular, with . . . most of the act being effective on July 1,1991, the benefit levels being changed effective October 1, 1991, and it would not — it would be prospective, everyone who [is] on the benefits would be grandfathered under those existing benefits . . . .” 34 H.R. Proc., Pt. 24, 1991 Sess., p. 9039, remarks of Representative Joseph A. Adamo. Although Adamo’s comments concerned all of P.A. 91-339, which altered compensation in ways other than the computation of COLAs,9 his assertions that that act would be applied prospectively and that persons currently receiving benefits would be grandfathered support a reading of the statute that protects COLAs that had been received by claimants prior to October 1, 1991.
*685Clearly, the legislature did not enact P.A. 91-339, § 27, with the intent to reduce drastically a claimant’s adjusted compensation rate. We therefore conclude that § 50 lends ambiguity to P.A. 91-339, § 27, and that a literal reading of § 27 would result in its improper application. We conclude, rather, that P.A. 91-339 should be applied to preserve the COLA effective October 1, 1990,10 for claimants who had been receiving COLAs prior to October 1, 1991.
We cannot agree, however, with the plaintiffs contention that she is entitled to have her COLAs determined in the future by the same method of calculation that existed on the date of her injury. In support of her contention, the plaintiff cites the “date of injury” rule and General Statutes §§ 1-1 (u) and 55-3. We summarized the date of injury rule in Iacomacci v. Trumbull, 209 Conn. 219, 222, 550 A.2d 640 (1988). There we considered the effect of a 1978 amendment to the Workers’ Compensation Act: “By the time Public Acts 1978, No. 78-369, was enacted, we had made clear through earlier decisions our view that new workers’ compensation legislation affecting rights and obligations as between the parties, and not specifying otherwise, applied only to those persons who received injuries after the legislation became effective, and not to those injured previously. This date of injury rule was first referred to in 1916, in Schmidt v. O.K. Baking Co., 90 Conn. 217, 220-21, 96 A. 963 (1916). In 1921, we stated that ‘[t]he obligations of the employer to dependents of an employee in case of the death of an injured employee are . . . fixed and determined by the statute in force at the time of injury.’ Quilty v. Connecticut Co., 96 *686Conn. 124, 127, 113 A. 149 (1921).” Iacomacci v. Trumbull, supra, 222.11
The date of injury rule functions as a presumption of legislative intent within the workers’ compensation context, similar to the general presumption against retroactive application of a statute. “[W]e consistently have expressed reluctance to construe statutes retroactively where the statutes affect substantial changes in the law, unless the legislative intent clearly and unequivocally appears otherwise.” State v. Lizotte, 200 Conn. 734, 741, 517 A.2d 610 (1986). In Iacomacci, we noted the date of injury rule’s presumptive status: “[N]ew workers’ compensation legislation affecting rights and obligations as between the parties, and not specifying otherwise, applies] only to those persons who received injuries after the legislation became effective, and not to those injured previously.” (Emphasis added.) Iacomacci v. Trumbull, supra, 209 Conn. 222. As recently as 1994, we noted that the date of injury rule was a presumption subject to the express intent of the legislature. See Civardi v. Norwich, 231 Conn. 287, 293 n.8, 649 A.2d 523 (1994).
The legislature is presumed to know of our interpretation of the workers’ compensation statutes and to know that it must make its intention clear if it intends to override the date of injury rule. We presume “that the legislature [was] mindful of judicial construction relevant to . . . legislation it enact[ed].” Murach v. Planning & Zoning Commission, 196 Conn. 192, 200 n.14, 491 A.2d 1058 (1985); Nationwide Ins. Co. v. Gode, 187 Conn. 386, 395 n.7, 446 A.2d 1059 (1982), overruled in *687part on other grounds, Covenant Ins. Co. v. Coon, 220 Conn. 30, 36 n.6, 594 A.2d 977 (1991). “ ‘In the interpretation of a statute, a radical departure from an established policy cannot be implied. It must be expressed in unequivocal language.’ Jennings v. Connecticut Light & Power Co., 140 Conn. 650, 667, 103 A.2d 535 (1954) . . . .” (Citations omitted.) State v. Ellis, 197 Conn. 436, 459, 497 A.2d 974 (1985).
The legislature, however, has demonstrated its ability to overcome the presumption of the date of injury rule when amending the Workers’ Compensation Act. Public Acts 1969, No. 696, § 5, added COLAs to compensation benefits for total incapacity “as a result of an injury sustained prior to October 1, 1969” — before the effective date of the act. Further, Public Acts 1977, No. 77-554, § 1, made the fund responsible for COLAs that were to be added to death benefits “as a result of death arising out of a compensable injury occurring on or before September 30,1977” — again, before the effective date of the act.
We conclude that it was the intention of the legislature to make P.A. 91-339, § 27, applicable to claimants injured prior to October 1, 1991, when it amended § 31-307a (a) to provide as follows: “The weekly compensation rate of each employee entitled to receive compensation under section 31-307 as a result of an injury sustained on or after October 1, 1969 . . . shall be adjusted . . . .” (Emphasis added.) The language in the statute is unequivocal, and there is nothing in the legislative history that suggests a different conclusion. Any presumption against having P.A. 91-339, § 27, apply to those injured before 1991 must therefore give way to the expressed intent of the legislature to apply the amended COLA provision to claimants injured before the effective date of the act.
In support of her position, the plaintiff also cites §§1-1 (u) and 55-3 and case law concerning judicial *688application of substantive and procedural changes in the law. Section 1-1 (u) provides: “The passage or repeal of an act shall not affect any action then pending.” We have interpreted § 1-1 (u) as reflecting the general rule concerning the effect of a statute on a pending action. “The situation is not within the provision of [§ 1-1 (u)] of the General Statutes, that ‘[t]he passage or repeal of an act shall not affect any action then pending,’ for this is ‘merely declaratory of a rule of construction’ and not applicable where a legislative intent to the contrary appears. Neilson v. Perkins, 86 Conn. 425, 427, 85 Atl. 686 [1913].” E. M. Loew’s Enterprises, Inc. v. International Alliance of Theatrical Stage Employees, 127 Conn. 415, 420, 17 A.2d 525 (1941). Section 1-1 (u) and our interpretation of it is a rule of construction, an aid in construing statutes, and not a rule that preempts the legislature’s clearly expressed intent.
Section 55-3 provides: “No provision of the general statutes, not previously contained in the statutes of the state, which imposes any new obligation on any person or corporation, shall be construed to have a retrospective effect.” We have stated that: “The ‘obligations’ referred to in the statute are those of substantive law. Nagle v. Wood, 178 Conn. 180, 186, 423 A.2d 875 (1979). Thus, we have uniformly interpreted § 55-3 as a rule of presumed legislative intent that statutes affecting substantive rights shall apply prospectively only. Westport v. State, 204 Conn. 212, 219, 527 A.2d 1177 (1987); Schieffelin & Co. v. Department of Liquor Control, 194 Conn. 165, 174, 479 A.2d 1191 (1984); Enfield Federal Savings & Loan Assn. v. Bissell, 184 Conn. 569, 571, 440 A.2d 220 (1981). The legislature only rebuts this presumption when it ‘clearly and unequivocally’ expresses its intent that the legislation shall apply retrospectively. State v. Lizotte, [supra, 200 Conn. 741]; Schieffelin & Co. v. Department of Liquor Control, supra, 174 . . . .” (Citation omitted; internal quotation *689marks omitted.) Darak v. Darak, 210 Conn. 462, 467-68, 556 A.2d 145 (1989); see Little v. Ives, 158 Conn. 452, 457, 262 A.2d 174 (1969) (“[t]he presumption is that statutes affecting substantive rights are intended to operate prospectively, and to furnish a rule for future cases only, unless they contain language unequivocally and certainly embracing past transactions”). In light of the legislature’s clearly expressed intention in P.A. 91-339, § 27, to have it apply to all employees injured “on or after October 1, 1969,” we conclude that the legislature intended § 27 to apply to the plaintiff and all those similarly situated.
“We have regularly recognized the right of the legislature retroactively to make legal and regular that which was previously illegal and irregular, provided that vested rights are not unjustly abrogated. C.S.E.A., Inc. v. Connecticut Personnel Policy Board, 165 Conn. 448, 454-55, 334 A.2d 909 (1973); Carvette v. Marion Power Shovel Co., 157 Conn. 92, 95-96, 249 A.2d 58 (1968) . . . .” (Citations omitted.) Enfield Federal Savings & Loan Assn. v. Bissell, supra, 184 Conn. 572. Our question then becomes whether the legislature, when it enacted Public Acts 1969, No. 696, § 5 (codified at General Statutes § 31-307a),12 created a vested right in the plaintiff to have her future COLAs calculated by the same method of calculation that existed on the date of her injury. “When the legislature intends to surrender *690its power of amendment and revision by creating a contract and thereby binding future legislatures, it must declare that intention in clear and unambiguous terms. A relinquishment of this authority should not occur by legislative inadvertence or judicial implication.” (Emphasis added.) Pineman v. Oechslin, 195 Conn. 405, 415, 488 A.2d 803 (1985). We do not believe that, as enacted in 1969, the language in § 31-307a (a) — simply providing that “[t]he weekly compensation rate of each employee . . . shall be adjusted annually as provided herein as of the following October first, and each subsequent October first, to provide such injured employee with a cost-of-living adjustment in his weekly compensation rate” — indicates an intention on the part of the legislature to create a vested, contractual-like right to have one’s COLA perpetually calculated as it was calculated on the date of injury.
The plaintiff next contends that Public Acts 1993, No. 93-228, § 21 (P.A. 93-228), which amended General Statutes § 31-309 (a), is relevant to our interpretation of P.A. 91-339, § 27. She claims the following language is pertinent: “[Wjeekly compensation received by an injured employee whose injury occurred before July 1, 1993, shall be computed according to the provisions of the law in effect at the time of his injury.” Public Acts 1993, No. 93-228, § 21. Because the definition of “compensation” includes “adjustment in benefits,”13 the plaintiff argues, the legislature clearly intended COLAs to be determined according to the law in effect on the date of injury. In further support of this argument, the plaintiff refers to an opinion letter of the attorney general, which interpreted that portion of P.A. 93-228 that altered the method for determining the maximum compensation rate for the ensuing years.14 The attorney *691general stated: “COLAs for 1994 and 1995 should be computed in the same manner that COLAs were computed for 1993, i.e., by comparing the maximum compensation rates under § 31-309 using 150% of the average production wage formula (the law in effect for injuries occurring prior to July 1, 1993) and applying whatever percentage increase there is to the claimant’s weekly compensation rate.” (Emphasis added.)
We find neither the plaintiffs argument concerning P.A. 93-228 nor the attorney general’s letter compelling. In his letter, the attorney general addressed only the 1993 act and the proper method of computing the maximum compensation rate. Although the maximum compensation rate is used in calculating COLAs, the method of computing the maximum compensation rate is not an issue in this case. The attorney general’s opinion letter, therefore, is inapposite.
The plaintiffs interpretation of the language in P.A. 93-228 and her attempt to utilize it to construe P.A. 91-339 is similarly inapposite. Public Act 93-228 addressed only the calculation of the maximum compensation rate and not the method of calculation of COLAs. The plaintiff would have us interpret P.A. 93-228, which addresses only one variable in the COLA equation, as evidence of the legislature’s position on every variable in the COLA equation and its application date. We do not construe the language of P.A. 93-228 as supporting such a broad interpretation, particularly when we are confronted with unambiguous language in P.A. 91-339, § 27, that clearly and unequivocally makes § 27 applicable to claimants who were injured before its effective date.15 In sum, we conclude that a perennial application *692of the flat dollar COLA for claimants injured before October 1, 1991, the effective date of P.A. 91-339, § 27, is not the appropriate interpretation of § 31-307a (a). Rather, we construe P.A. 91-339, § 27, as mandating percentage-based COLAs commencing October 1,1991, for all recipients of COLAs.
The proper balance between preserving the “accrued” flat rate adjustments, as we believe we are bound to do by P.A. 91-339, § 50, and fairly construing P.A. 91-339, § 27, can be achieved by employing the following method of calculating COLAs. In order to arrive at the proper percentage of increase, the current maximum compensation rate should be divided by the maximum compensation rate effective on October 1, 1990 (the last maximum compensation rate before P.A. 91-339, § 27, became effective); that figure should be multiplied by the claimant’s base compensation rate, i.e., the compensation rate as of the date of injury; the resulting figure should then be added to the claimant’s COLA on October 1, 199016 (this recognizes and preserves the claimant’s accrued COLAs). This sum is the claimant’s current adjusted compensation rate.17 This method preserves the 1990 flat dollar COLA by simply adding it to the claimant’s adjusted compensation rate as calculated by the statute.18 Moreover, it remains true *693to the statute by increasing the compensation rate that the injured employee was entitled to receive at the date of injury by the percentage of the increase in the maximum compensation rate.19
The only arguable alternative to the method set forth in the preceding paragraph for determining COLAs for claimants injured before October 1,1991, that preserves the 1990 COLA is the Arcudi method, which was followed by the payors and payees for four years.20 The Arcudi method protected a claimant’s “accrued” flat dollar adjustments, but determined the subsequent percentage adjustments by multiplying the maximum compensation rate’s percentage increase from the previous year by the adjusted compensation rate of the claimant for the previous year (the previous year’s adjusted compensation rate would include “accrued” COLAs to that date).21 Therefore, unlike the method we adopt, which *694references the compensation rate at the time of injury to determine the present year’s percentage adjustment, the Arcudi method referenced a claimant’s base compensation rate plus all “accrued” COLAs to date to determine the present year’s percentage adjustment. In essence, the Arcudi method continually updated the referenced compensation rate by adding to it the yearly dollar adjustments. This method not only protected the flat dollar 1990 COLA, but it also allowed that adjustment and all future percentage adjustments to be figured into subsequent COLAs as part of the referenced compensation rate. The legislature was clear in its intent to preserve a claimant’s flat dollar COLA increases to 1990, but there is no support for the proposition that the 1990 flat dollar COLA and future COLAs must or should be used to increase the referenced compensation rate in a determination of the present years’ adjustment. Our method of calculation more nearly conforms to the statute because it references the compensation rate at the time of injury; or as the statute provides, “the weekly compensation rate which the injured employee was entitled to receive at the date of the injury . . . ,”22
*695We conclude, therefore, that COLAs for claimants injured prior to October 1, 1991, should be calculated according to the following formula: the percentage of increase of the maximum compensation rate is to be obtained by dividing the current maximum compensation rate by the maximum compensation rate effective on October 1,1990; that figure should then be multiplied by the claimant’s base compensation rate and then added to the claimant’s COLA as of October 1, 1990.
The plaintiffs COLAs should be adjusted from the date of reduction in December, 1995, to the present in accordance with the method set out in the preceding paragraph.
The judgment of the board is reversed and the case is remanded for further proceedings in accordance with this opinion.
In this opinion NORCOTT, PALMER and MCDONALD, Js., concurred.
The Workers’ Compensation Act can be found in chapter 568 of the General Statutes, §§ 31-275 through 31-355a.
General Statutes (Rev. to 1991) § 31-307a (a), as amended by P.A. 91-339, § 27, provides: “Cost-of-living adjustment in compensation rates, (a) The weekly compensation rate of each employee entitled to receive compensation under section 31-307 as a result of an injury sustained on or after October 1, 1969, which totally disables the employee continuously or intermittently for any period extending to the following October first or thereafter, shall be adjusted annually as provided in this subsection as of the following October first, and each subsequent October first, to provide the injured employee with a cost-of-living adjustment in his weekly compensation rate as determined as of the date of the injury under section 31-309. If the maximum weekly compensation rate as determined under the provisions of section 31-309, to be effective as of any October first following the date of the injury, is greater than the maximum weekly compensation rate prevailing as of the date of the ir\jury, the weekly compensation rate which the injured employee was entitled to receive at the date of the injury shall be increased by the percentage of the increase in the maximum weekly compensation rate required by the provisions of section 31-309 from the date of the injury to such October first. The cost-of-living increases provided under this subsection shall be paid by the employer without any order or award from the commissioner. The adjustments shall apply to each payment made in the next succeeding twelve-month period commencing with the October first next succeeding the date of the injury.”
Section 31-307a (a) was later amended by Public Acts 1993, No. 93-228, to deny COLAs for injuries resulting in total incapacity that occurred subsequent to the passage of the act.
General Statutes § 31-301b provides: “Anyparty aggrievedby the decision of the Compensation Review Board upon any question or questions of law arising in the proceedings may appeal the decision of the Compensation Review Board to the Appellate Court.”
For the purposes of this opinion, “base compensation rate” means the actual cash benefit claimants are entitled to receive on the date of their injury.
General Statutes (Rev. to 1991) § 31-307a, prior to the 1991 amendment, provided in relevant part: “Cost-of-living adjustment in compensation rates, (a) The weekly compensation rate of each employee entitled to receive benefits under section 31-307 as a result of an injury sustained on or after October 1, 1969 . . . shall be adjusted annually as provided herein as of the following October first, and each subsequent October first, to provide such injured employee with a cost-of-living adjustment in his weekly compensation rate as determined as of the date of the injury under section 31-309. If the maximum weekly compensation rate as determined under the provisions of section 31-309, to be effective as of any October first following the date of the injury, is greater than the maximum weekly compensation rate prevailing at the time of injury, the weekly compensation rate which the injured employee was entitled to receive at the time of the injury shall be increased by the (Miar amount of the increase in the maximum weekly compensation rate required by the provisions of section 31-309 from the date of the injury to such October first. . . .” (Emphasis added.)
The maximum compensation rate is determined according to the provisions in General Statutes § 31-309.
Prior October 1, 1991, COLAs for total incapacity were determined by calculating the dollar amount of increase in the maximum compensation rate, from the claimant’s date of injury to the present, and increasing the *680claimant’s base compensation rate by the same dollar amount. Public Act 91-339, § 27, replaced the flat dollar increase method with a percentage increase method.
As an aid to understanding the various methods discussed in this opinion, we will present these methods in the form of a formula:
Max™™"* x cRi>ase _ AGR'"™"*, where Max1)01
Max""1™1 = the current maximum compensation rate,
MaxD<)I = the maximum compensation rate on the date of injury,
CRtosp _ Qjg claimant’s base compensation rate, and
Acr™“™‘ = the claimant’s current adjusted compensation rate.
General Statutes § 31-275 (4), which defines compensation for purposes of the Workers’ Compensation Act, provides as follows: “ ‘Compensation’ means benefits or payments mandated by the provisions of this chapter, including, but not limited to, indemnity, medical and surgical aid or hospital and nursing service required under section 31-294d and any type of payment for disability, whether for total or partial disability of a permanent or temporary nature, death benefit, funeral expense, payments made under the provisions of section 31-284b, 31-293a or 31-310, or any adjustment in benefits or payments required by this chapter.”
The formula for determining a claimant’s base compensation rate under General Statutes § 31-307 (a) was altered by § 26 of P.A. 91-339.
We deliberately choose not to characterize the COLAs as having accrued on a yearly basis because the statute belies that characterization. The statute consistently adds the current COIA to the claimant’s base compensation rate, and not the previous year’s adjusted compensation rate. General Statutes § 31-307a (a).
In Iacomacci v. Trumbull, supra, 209 Conn. 222-23, we cited additional cases in which we applied the date of injury rule. See Rossi v. Thomas F. Jackson Co., 120 Conn. 456, 460, 181 A. 539 (1935); Farmer v. Bieber-Goodman Corp., 118 Conn. 299, 302-303, 172 A. 95 (1934); Panico v. Sperry Engineering Co., 113 Conn. 707, 709, 156 A. 802 (1931); Preveslin v. Derby & Ansonia Developing Co., 112 Conn. 129, 142, 151 A. 518 (1930).
COLAs were first introduced in Public Acts 1967, No. 842, § 23, which provided in relevant part: “Each employee entitled to receive benefits under section 31-307 as a result of an injury sustained on or after October 1, 1967, shall be increased by that percentage, if any, which equals the percentage of increase in the average wage of employees covered by chapter 567 of the general statute's on that date or as of any subsequent June thirtieth, as determined under the provisions of section 17 of this act over the average wage of employees covered by said chapter 567 in effect at the time of the injury. . . .”
The COLA provision was extensively rewritten in 1969 and was identical to the wording in § 31-307a (a) at the time of the plaintiffs injury.
See footnote 8.
Opinion letter of Richard Blumenthal, attorney general, to Jesse Frank!, chair of the workers’ compensation commission, November 2, 1995.
Additionally, the 1993 legislature did not amend § 31-307a (a) even though Arcudi had interpreted the statute as applying a percentage formula, rather than a flat dollar formula, to claimants injured before October 1,1991. This lack of legislative action in the face of the commissioner’s interpretation further undermines the plaintiffs argument regarding the meaning of the 1993 act.
Technically, a claimant’s COLA on October 1, 1990, is the difference between the claimant’s compensation rate on tire date of injury and the claimant’s adjusted compensation rate on October 1, 1990. In the language of the industry, this would be the claimant’s “accrued” COLAs to October 1, 1990.
Max x cflta* + COLA™0 = ACRcurrc“* l, where Maxlm
Maxcurrcl,t = the current maximum compensation rate,
Max1990 = the maximum compensation rate on October 1, 1990,
CRbasc _ tRg claimant’s base compensation rate,
COLA1990 = the claimant’s COLA on October 1, 1990, and
ACRom™1 _ tRg claimant’s current adjusted compensation rate.
Our calculation determines the percent increase from 1990 to the present date and not from the date of injury. Determining the percent increase from the date of injury in addition to preserving the 1990 COLA would, in essence, *693award two COLAs for each year prior to the amendment of the statute, a flat dollar increase and a percent increase. This certainly was not the legislature’s intention when it enacted P.A. 91-339.
Under our method of calculation, the plaintiffs biweekly compensation rate in December, 1995 (the date on which the fund altered the plaintiffs compensation rate from $518.21 to $316.04) would be $495.62. Using the maximum compensation rates for injuries occurring October 1,1979, through September 30, 1987, as provided by the workers’ compensation commissioner, we calculated the plaintiffs December, 1995 rate as follows: where
Max"™: = $584 (the maximum compensation rate on October 1, 1995),
Max1990 = $479,
OR1»-"' = $93.35, and
COLA1999 = $134 (maximum compensation rate in 1990 [$479] - maximum compensation rate on date of injury [$345]);
then $584 x $93.35 + $434 = $247.81 (weekly), $495.62 (biweekly) $479
As noted by the fund, the Arcudi method itself was open to interpretation. Payors used two fundamentally different methods of calculation in an attempt to comply with the Arcudi method.
ft/TV-i/yOiiuent __ max xacrp™™*= ACR'"llmt, where Max11™'"
Max™"™' = the current maximum compensation rate,
MaxSI”“"u' = the maximum compensation rate of the previous year,
ACRpl™“‘' = the claimant’s base compensation rate, and
ACRcuuent = the claimant’s current acjjusted compensation rate.
In its disagreement with our calculation, the dissent relies heavily on (1) the legislature’s silence with respect to Arcudi’s interpretation when the legislature further amended § 31-307a (a) in 1993 to disallow COLAs for those injured on or after July 1,1993, and (2) the agency’s consistent interpretation of the statute. While we acknowledge these interpretive presumptions, we nonetheless decline to adopt the Arcudi method for two reasons. First, the industry’s two interpretations of the Arcudi method; see footnote 20 of this opinion; undermine the presumption that the legislature has concurred with a particular interpretation. Second, there should be no deference to the agency’s interpretation because the agency itself has issued inconsistent interpretations (compare the Arcudi method, Wolfe v. JAB Enterprises, Inc., supra, 14 Conn. Workers’ Comp. Rev. Op. 127, and Gil v. Courthouse One, Compensation Review Board, Case No. 3278 CRB-6-96-3 [May 1, 1996]); Glastonbury Education Assn. v. Freedom of Information Commission, 35 Conn. App. 111, 117, 643 A.2d 1320 (1994), aff'd, 234 Conn. 704, 663 A.2d 349 (1995); and the question of law before us in this case has not previously been subject to judicial scrutiny. Dept. of Administrative Services v. Employees’ Review Board, 226 Conn. 670, 679, 628 A.2d 957 (1993) (“when *695a state agency’s determination of a question of law has not previously been subject to judicial scrutiny . . . the agency is not entitled to special deference”); see Connecticut Light & Power Co. v. Dept. of Public Utility Control, 210 Conn. 349, 357, 554 A.2d 1089 (1989). The confusion concerning the proper application of P.A. 31-339, § 27, undercuts any reliance on the presumptions cited by the dissent, particularly in light of the clear and unambiguous language in P.A. 91-339, § 27, that provides: “[T\he weekly compensation ra.te which the injured employee was entitled to receive at the date of the injury shall be increased by the percentage of the increase in the maximum weekly compensation rate . . . .” (Emphasis added.)