(2) Computation of inflation adjustment factor and reference price (A) In general The Secretary shall, not later than April 1 of each calendar year, determine and publish in the Federal Register the inflation adjustment factor and the reference price for such calendar year in accordance with this paragraph. (B) Inflation adjustment factor The term “inflation adjustment factor” means, with respect to a calendar year, a fraction the numerator of which is the GDP implicit price deflator for the preceding calendar year and the denominator of which is the GDP implicit price deflator for the calendar year 1992. The term “GDP implicit price deflator” means the most recent revision of the implicit price deflator for the gross domestic product as computed and published by the Department of Commerce before March 15 of the calendar year. (C) Reference price The term “reference price” means, with respect to a calendar year, the Secretary’s determination of the annual average contract price per kilowatt hour of electricity generated from the same qualified energy resource and sold in the previous year in the United States. For purposes of the preceding sentence, only contracts entered into after December 31, 1989 , shall be taken into account.