Mich. Comp. Laws § 18.1355

Sec. 355. (1) The transfer into or out of the fund as provided in section 352 for each fiscal year beginning after September 30, 1978, may be adjusted in light of revision in the annual growth rate for the calendar year upon which that transfer was made. If an adjustment is made, it shall be implemented by an appropriation bill enacted into law. (2) For a transfer into the fund, the adjustment, if made, shall be directly proportional to an increase or decrease in the annual growth rate. (3) The basis for an adjustment under this section shall be a change in the personal income level for that calendar year as determined by the bureau of economic analysis of the United States Department of Commerce or its successor in the last report it makes before April 30 of the fiscal year in which that calendar year ended. The adjustment, if made, shall be effective on June 1 of the fiscal year in which the transfer is made.