(a) With respect to any fiscal year, the Secretary shall provide a percentage increase in the rates payable under sections
3532,
3534 (b), and
3542 (a) of this title equal to the percentage by which
(1) the Consumer Price Index (all items, United States city average) for the 12-month period ending on the June 30 preceding the beginning of the fiscal year for which the increase is made, exceeds
(2) such Consumer Price Index for the 12-month period preceding the 12-month period described in paragraph (1).