Every allowance based on the average monthly compensation earnable by the member during the 10 years prior to retirement, and payable for time commencing on February 1, 1957, to or on account of persons who were retired, as members under Section 8.567, for disability resulting from bodily injury received in the performance of duty, shall be adjusted to the amount it would be, if it had been based on the monthly compensation fixed by the Board of Supervisors as of July 1, 1956, for the rank or position held by such retired member in the fire department prior to retirement. This section does not authorize any decrease in any allowance from the amount being paid as of February 1, 1957, nor does this section give any retired member, or any beneficiary of such member, or his successors in interest, any claim against the City and County for any increase in any allowance paid or payable for the time prior to February 1, 1957. Adjustment in reserves under allowances which are changed according to this section, shall be made on the basis of current interest rate and mortality tables.
The increase in the retirement allowance shall be apportioned according to service rendered by the member in the same manner that the allowance prior to increase was apportioned. Contributions to the Retirement System, necessary for the payment of the increase of the portion of the retirement allowances which is paid from reserves held by the Retirement System, shall be provided from the reserves held by the Retirement System on account of members under Section 8.568, the necessary amount being transferred upon February 1, 1957, from said reserves to the reserves held by the Retirement System to meet the obligations on account of benefits that have been granted and on account of prior service of members. The contribution being required of the City and County currently, as a percentage of salaries of persons who are members under Section 8.568, shall be increased to a percentage determined by the actuary as necessary to replace the reserves so transferred. Contributions to the Retirement System necessary for the payment of said increases with reference to current and prior service portions of the allowance which are not paid from reserves held by the Retirement System, shall be paid to the system by the City and County by annual appropriations, provided that such appropriation for any year shall not be less than the amount disbursed during that year on account of said increases.