Any monthly service or disability pension which became effective before January 1, 1979, and is payable on July 23, 1982, and any survivor pension based on a former service or disability pension that was effective prior to January 1, 1979, shall be increased effective July 1, 1982, in accordance with the following schedule:

Year Service or Disability Percent Increase in Pension
?Pension Becomes Effective Effective 7/1/82
Prior to 1971 31%
1971 21%
1972 19%
1973 16%
1974 10%
After 1974 5%