Whenever there is an increase in benefit amounts payable under title II of the Social Security Act (
42 U.S.C. 401 et seq.) as a result of a determination made under section 215(i) of such Act (
42 U.S.C. 415(i)), the Secretary shall, effective on the date of such increase in benefit amounts, increase the amount payable under paragraph (1), as such amount was in effect immediately prior to the date of such increase in benefit amounts, by the same percentage as the percentage by which such benefit amounts are increased. Any increase in a dollar amount under this paragraph shall be rounded down to the next lower whole dollar amount.