Section 38.1309 - Calculating member's final average compensation; effective date of section(1) The definition of final average compensation under section 4 as that section existed prior to Act No. 91 of the Public Acts of 1985 shall be used to calculate a member's final average compensation if it produces a higher result than the amount calculated pursuant to either section 4 or section 43c.(2) This section shall take effect July 10, 1985.Add. 1986, Act 123, Imd. Eff. 6/2/1986 ;--Am. 1989, Act 194, Imd. Eff. 8/25/1989.