Mich. Comp. Laws § 38.1404

Sec. 104. (1) The percentage increase to the monthly retirement allowance payable to a retirant or retirement allowance beneficiary under either section 27f of chapter I or section 25c of chapter II of former Act No. 136 of the Public Acts of 1945, is continued as provided in this section. (2) The monthly retirement allowance payable to a retirant or retirement allowance beneficiary after September 30, 1976, who was on the rolls for September 30, 1976, is supplemented as follows: Supplement for Effective Date of Retirement October 1, 1976 and 1977 July 1, 1975, to June 30, 1976 1% July 1, 1974, to June 30, 1975 2% July 1, 1973, to June 30, 1974 3% July 1, 1972, to June 30, 1973 4% July 1, 1971, to June 30, 1972 5% July 1, 1970, to June 30, 1971 6% July 1, 1969, to June 30, 1970 7% July 1, 1968, to June 30, 1969 8% Before July 1, 1968 8%