(a) As used in this part, unless the context otherwise requires:

(1) “Assessment ratio in effect” means that assessment ratio being applied by the comptroller of the treasury in assessing gas system property of private gas corporations for ad valorem taxation or, if such assessment function ceases to be performed by the comptroller of the treasury, that assessment ratio applied by any authorized department, agency, or official of the state empowered to so apply such an assessment ratio in assessing gas system property;
(2)

(A) “Average of revenue less power cost from gas system operations for the preceding three (3) fiscal years” means an amount derived by:

(i) Determining for each of the three (3) fiscal years immediately preceding the beginning of the current fiscal year, the gas system’s total operating revenues for the year, less any operating revenue amounts deemed uncollectible and written off for the year, net of any such amounts reinstated during the year that had been written off in any prior fiscal year, and taking into account any extraordinary items attributable to any prior fiscal year‘s total operating revenue or uncollectible amounts, and totaling the three (3) yearly amounts so determined;
(ii) Determining for each of the same three (3) fiscal years described in subdivision (a)(2)(A)(i) the total costs of purchased gas, excluding any charges for facilities’ rentals and taking into account any extraordinary items attributable to any prior fiscal year’s purchased gas costs or facilities’ rental charges, and totaling the three (3) yearly amounts so determined; and
(iii) Subtracting the total in subdivision (a)(2)(A)(ii) from the total in subdivision (a)(2)(A)(i) and dividing the resulting remainder by three (3);
(B) For purposes of subdivision (a)(2)(A), “any prior fiscal year” means any fiscal year beginning on or after July 1, 1984. Also, for purposes of subdivision (a)(2)(A), all amounts described are those attributable only to gas system operations within Tennessee;
(3) “Equalized property tax rate” of any taxing jurisdiction means the actual ad valorem property tax rate in effect multiplied by the applicable state, county, or municipal appraisal ratio for such taxing jurisdiction as determined by the state board of equalization, known as “state board” in this part. “Appraisal ratio” means the ratio of appraised values of record to one hundred percent (100%) of current values that are to be derived in accordance with applicable state law for use in ad valorem property tax determinations each tax year. For purposes of this part, the equalized property tax rate that is in effect for any taxing jurisdiction as of the beginning of any gas system fiscal year shall be the same as an equalized property tax rate calculated for such taxing jurisdiction for that tax year, which is the calendar year, in which the fiscal year begins, using the actual property tax rate in effect for, and the appraisal ratio applicable for, such taxing jurisdiction for such tax year;
(4) “Fiscal year” means the year beginning July 1 of each calendar year;
(5) “Gas operations” means all activities associated with the establishment, development, and administration of a gas system and the business of supplying gas and associated services to the public, including, but not limited to, the generation, purchase, and sale of gas energy and the purchase, use, and consumption of gas energy by ultimate consumers;
(6) “Gas system” means all tangible and intangible property and resources of every kind and description used or held for use in the purchase, generation, transmission, distribution, and sale of gas energy;
(7) “Municipality” means any incorporated city or town, metropolitan government, or county that now or hereafter owns and operates a gas system;
(8) “Net plant value of the gas system plant” means the depreciated original cost of the gas plant, in service and held for future use, and the book value of construction work in progress, all as shown on the books of the gas system and all of which are for use in the transmission, and the distribution of gas;
(9) “Private act” includes, without limitation, the charter and any amendments to the charter of any home rule municipality or any metropolitan government;
(10) “Supervisory body” means any board or other agency of a municipality established to supervise the management and operation of its gas system and operations, or, in the absence of a board or other agency, the governing body of the municipality; and
(11) “Taxing jurisdiction” means any county, incorporated city or town, or metropolitan government in Tennessee having the power to levy taxes, or any special taxing district in Tennessee on behalf of which ad valorem property taxes may be levied, for the support of governmental and related activities and services.
(b) Terms appearing in this section, except where specifically defined, have the meanings defined or ascribed to them in the uniform system of accounts applicable to local governments.