percent change in the price index
(3) the term “percent change in the price index”, as used with respect to a year, means the percentage derived by— (A) reducing— (i) the price index for the base quarter of such year, by (ii) the price index for the base quarter of the preceding year in which an adjustment under this subsection was made; (B) dividing the difference under subparagraph (A) by the price index referred to in subparagraph (A)(ii); and (C) multiplying the quotient under subparagraph (B) by 100.