(a) The monthly allowances payable to retired members, disabled members, and beneficiaries are increased as of January 1, 1980, for those persons receiving allowances with respect to members who retired or died prior to June 30, 1973, to the amount that results when the initial allowance that was received by those members is multiplied by the percentage set forth opposite the year of retirement or death in the following schedule:
Period During Which
Retirement or Death Occurred
Percentage
On or before June 30, 1958
180.4
12 months ending June 30, 1959
175.8
12 months ending June 30, 1960
172.2
12 months ending June 30, 1961
169.8
12 months ending June 30, 1962
167.8
12 months ending June 30, 1963
165.5
12 months ending June 30, 1964
163.0
12 months ending June 30, 1965
159.8
12 months ending June 30, 1966
156.7
12 months ending June 30, 1967
153.1
12 months ending June 30, 1968
147.5
12 months ending June 30, 1969
141.6
12 months ending June 30, 1970
134.5
12 months ending June 30, 1971
128.7
12 months ending June 30, 1972
124.5
12 months ending June 30, 1973
119.6
(b) For those retired members, disabled members, and beneficiaries receiving an allowance with an effective date prior to July 1, 1965, the initial allowance, for purposes of this section, shall be deemed to be the allowance payable on July 1, 1965. However, for purposes of determining the allowance payable under this section, the percentage corresponding to the actual year of retirement shall be applied.