The board shall before April of each year determine whether there has been an increase or decrease in the cost of living as provided in this section. Notwithstanding

Section or any other provision of this

chapter (commencing with

Section 31450), every retirement allowance, optional death allowance, or annual death allowance payable to or on account of any member of the plan created by this

article who retires at or beyond normal retirement age or dies shall, as of April 1st of each year, be increased or decreased by a percentage of the total allowance then being received found by the board to approximate to the nearest one-half of percent the percentage of annual increase or decrease in the cost of living as of January 1st of each year as shown by the then current Bureau of Labor Statistics Consumer Price Index for All Urban Consumers for the Los Angeles-Anaheim-Long Beach area, but such change shall not exceed percent per year; however, the amount of any cost-of-living increase or decrease in any year which is not met by the maximum annual change of percent in allowances shall be accumulated to be met by increases or decreases in allowances in future years; except that no decrease shall reduce the allowance below the amount being received by the member or his or her beneficiary on the effective date of the allowance.

No adjustment shall be made in the retirement allowance of a member who retires prior to attaining normal retirement age until the member attains normal retirement age.