OPINION
BILLINGS, Judge:{11 Hereules Incorporated (Hercules) appeals a final decision by the Utah State Tax Commission (Commission) imposing a sales tax on Hercules for nitrogen gas it purchased and used in manufacturing graphite fiber. We reverse.
~ BACKGROUND
1 2 Hercules purchased nitrogen gas which it used in manufacturing graphite fiber.1 The nitrogen gas is not used as a fuel in the manufacturing process and is not an ingredient in the product, but rather provides an atmosphere that prevents the carbon, the basic ingredient of the graphite fibers, from being consumed during the high-temperature manufacturing process.
*232T3 On March 30, 1998, the Auditing Division of the Utah State Tax Commission issued Hereules a Statutory Notice of Deficiency. The deficiency assessment was for Utah sales and use taxes in the amount of $522,131.52 covering the period January 1, 1994 to December 831, 1996.
' 4 Hercules conceded liability on all items in the deficiency assessment except the taxa-bility of its purchases of nitrogen gas used in its graphite fiber manufacturing process. Hercules argued that its purchase of nitrogen gas was excluded from taxation because, although the Utah tax code taxes purchases of "gas, electricity, heat, coal, fuel oil, or other fuels" for commercial or residential use, see Utah Code Ann. $ 59-12-108(1)(c) (1995), Hercules puts the nitrogen gas to industrial use and thus it is not taxable.
15 Following a formal adjudication, the Commission concluded the meaning of "gas" in section 59-12-108(1)(c) does not include nitrogen gas. Accordingly, the Commission concluded that Hereules' purchases of nitrogen gas were taxable as retail sales of tangible personal property. Hercules appeals.
ISSUE AND STANDARD OF REVIEW
16 At issue is whether the term "gas" under section 59-12-108 includes nitrogen gas. The Commission's interpretation of the tax code is a question of law, see Cache County v. State Tax Comm'n, 922 P.2d 758, 763 (Utah 1996), accordingly, we grant the Commission's interpretation no deference. See id.; see also Utah Code Ann. § 59-1-610(1)(b) (1996).
ANALYSIS
MEANING OF "GAS" IN TAX CODE
17 Hereules argues that its purchases of nitrogen gas fall under Utah Code Ann. §§ 59-12-108(1)(c) and (d) (1996). See-tions 59-12-108(1)(c) and (d) impose a tax on sales of "gas, electricity, heat, coal, fuel oil, or other fuels sold for residential use," id. § 59-12-108(1)(c) (emphasis added), or "commercial use," id. § 59-12-108(1)(d) (emphasis added). Hercules argues: (1) nitrogen is a gas; (2) sales of gas are only taxed if the gas is used residentially or commercially; (8) Hercules uses the gas industrially; and (4) therefore the sales are not taxable.2
T8 The Commission concedes that if "gas" in the subject taxing statute includes nitrogen gas then Hereules' position is correct. However, the Commission argues that "gas" as used in the statute was intended by the legislature to only include natural gas or at least only gas when used as a source of energy. Although the Commission's position is logical, it is not supported by our case law.3
T9 "[In construing any statute, we first examine the statute's plain language and resort to other methods of statutory interpretation, only if the language is ambiguous. Accordingly, we read the words of a statute literally ... and give the words their usual and accepted meaning." Gull Lab., Inc. v. State Tax Comm'n, 936 P.2d 1082, 1084 (Utah Ct.App.1997) (citations and internal quotations omitted). "When a statute fails to *233define a word, we rely on the dictionary to divine the 'usual meaning."" State v. Redd, 954 P.2d 230, 234 (Utah Ct.App.1998) (quoting Gull Lab., 936 P.2d at 1084).
1 10 Webster's Dictionary defines "gas" as "a fluid that has neither independent shape nor volume but tends to expand indefinitely." Webster's Third New International Dictionary 987 (1986). The dictionary meaning of "gas" is certainly broad enough to include nitrogen gas.4
11 The Commission also argues that the phrase in sections 59-12-103(1)(c) and (d) "or other fuels" modifies each term in the statute thus limiting gas to only gas used as a fuel. Again, this is a possible but unclear interpretation. This term "or other fuels" could also just as easily be read to modify only the term it follows, clarifying that "fuel oil" or other liquids used for fuel are subject to the statute.
112 Finally, and most important to our analysis, is our rule in taxation cases5 that "if any doubt exists as to the meaning of the statute, 'our practice is to construe taxation statutes liberally in favor of the taxpayer, leaving it to the legislature to clarify an intent to be more restrictive if such intent exists."" Wasatch County Bd. of Equalization v. State Tax Comm'n, 944 P.2d 370, 374 (Utah 1997) (quoting Salt Lake County v. State Tax Comm'n, 779 P.2d 1131, 1182 (Utah 1989)). Any intent to restrict the meaning of the term "gas" in the statute is not clear. Therefore, we construe the statute liberally in favor of the taxpayer, which leads us to conclude that the taxpayer, Hercules, should prevail.6
[ 13 Indeed, our conclusion gains additional support from the fact that in 1996 the legislature amended Utah Code Ann. § 59-12-104 to specifically include the term "natural gas." See $ 59-12-104(48) (1996).7 This makes clear that now only sales of natural gas are exempt from taxation when used for manufacturing purposes.
Ordinarily, "the presumption [is] that an amendment is intended to change existing legal rights." An exception to this presumption exists when the amendment "was intended to clarify a preexisting intention." In this case, however, "we find no indication in the ... amendment or elsewhere that the amendment was intended to clarify a preexisting intention." If anything, this legislative change supports the proposition that the statute previously meant something different from what it now says.
Visitor Info. Ctr. Auth. of Grand County v. State Tax Comm'n, 930 P.2d 1196, 1198 (Utah 1997) (quoting Madsen v. Borthick, 769 P.2d 245, 252 n. 11 (Utah 1988) (citing 1A Norman .J. Singer, Sutherland Statutory Construction § 22.30 (4th rev. ed.1985))); see also State v. Amador, 804 P.2d 1233, 1234 (Utah Ct.App.1990) (stating that "[elvery amendment not expressly characterized as a clarification carries the rebuttable presumption that it is intended to change existing legal rights and liabilities"). Thus, we presume that the statute, prior to amendment, did not exempt only natural gas from taxation to the exclusion of all other gases used for manufacturing purposes.8
1 14 Accordingly, we reverse and remand to the Commission for a re-caleulation of tazes due by Hercules in harmony with our decision.
T15 I CONCUR: GREGORY K. ORME, Judge.
. Hercules sells the graphite fiber for applications requiring high strength, lightweight material, for use primarily in the aerospace industry.
. Hercules additionally argues that a historical analysis of the tax code shows that the legislature means more than "natural gas" when it uses the term "gas." Hercules notes that a 1937 statute taxing payments made to "gas, electric, and heat corporations' specifically incorporated an existing provision defining "gas plant." See 1937 Utah Laws 111 at § 1 (emphasis added). That provision defined "gas plant" as "all real estate and fixtures and personal property owned, controlled, operated or managed in connection with or to facilitate the production, generation, transmission, delivery or furnishing of gas (matural or manufactured) for light, heat or power." Utah Rev.Stat. § 76-2-1(16) (1933) (emphasis added). Hercules argues that this provision was also incorporated by the 1943 forerunner to section 59-12-103(1)(c) (1996).
. We respecifully disagree with our able colleague in dissent when he states, "Hercules does not dispute the Commission's ruling under section 59-12-103(1)(a)," and that section 59-12-103(1)(c) is merely "peripheral." It is our reading of the record below and the briefs on appeal that both the Commission and Hercules agree that section 59-12-103(1)(c) controls as the more specific taxing statute. See Dairyland Ins. Co. v. State Farm Mut. Auto. Ins. Co., 882 P.2d 1143, 1146 (Utah 1994) (stating that when "two provisions address the same subject matier and one provision is general while the other is specific, the specific provision controls"). However, the Commission relied on the general retail sales taxing provision, section 59-12-103(1)(a), in its conclusion of law when it incorrectly concluded "gas" does not include nitrogen gas.
. The Commission concedes it has not treated oxygen gas as subject to taxation under the statute. It seems illogical that the Commission would tax nitrogen gas, as used by Hercules, and not oxygen gas in the same manner.
. We conclude that section 59-12-103(1)(c) is a taxing provision which defines those taxed to include those who use "gas" for a "commercial" or "residential" purpose but not those that use gas for a noncommercial or industrial purpose.
. The dissent's use of statutory construction to reach a different conclusion only supports our conclusion that the meaning of this statute is unclear and susceptible to several possible interpretations.
. The amendment specifically exempts from taxation "sales of natural gas, electricity, heat, coal, fuel oil, or other fuels for industrial use." Utah Code Ann. § 59-12-104(43) (1996).
. For example, "gas" could include methane found as natural gas or "manufactured" gases including methane, propane, butane, etc.