Sec. 6. The board shall do the following:
(1) Credit interest to the members' annuity savings accounts in the guaranteed fund (before January 1, 2017), actual earnings to the stable value fund (after December 31, 2016), and actual earnings to the alternative investment programs.
(2) After complying with subdivision (1), distribute any remaining undistributed income reserve as of the end of each accounting period as determined by the rules of the board.