(A) As of the end of each calendar year, the increase in the ratio of the Consumer Price Index to the index as of the prior December thirty-first must be determined.
(B)
(1) If the Consumer Price Index as determined pursuant to subsection (A) of this section increases by no more than one percent, the retirement allowance, inclusive of the supplemental allowances payable under the provisions of Sections 9-1-1910, 9-1-1920, and 9-1-1930, of each beneficiary in receipt of an allowance must be increased by a percentage equal to the increase in the index.
(2) If the Consumer Price Index as determined pursuant to subsection (A) of this section increases by more than one percent, then:
(a) the retirement allowance of each beneficiary in receipt of an allowance, inclusive of the supplement allowances payable under the provisions of Section 9-1-1910, 9-1-1920, and 9-1-1930, must be increased by one percent; and
(b) the retirement allowance may be further increased beyond one percent up to the lesser of the total percentage increase in the Consumer Price Index or four percent, to the extent that the additional liabilities because of the increase in allowances would not extend the amortization period to liquidate the unfunded actuarial accrued liability of the South Carolina Retirement System beyond thirty years. In considering this additional increase, the board shall consider unrealized investment gains and losses.
(C) The increase in retirement allowances commences the July first immediately following the December thirty-first that the increase in ratio was determined, and all increases in retirement allowances must be granted to these beneficiaries in receipt of a retirement allowance on July first immediately preceding the effective date of the increase. Any increase in allowance granted pursuant to this section must be included in the determination of any subsequent increases, irrespective of any subsequent decrease in the Consumer Price Index.
(D) The allowance of a surviving annuitant of a beneficiary whose allowance is increased under this section must, when and if payable, be increased by the same percent.
(E) For purposes of this section, "Consumer Price Index" means the Consumer Price Index for Wage Earners and Clerical Workers, as published by the United States Department of Labor, Bureau of Labor Statistics.