(1) The retirement board, in consultation with the department, shall engage an actuary, in conformance with section 261 of the management and budget act, 1984 PA 431, MCL 18.1261.

  (2) The actuary shall prepare an annual valuation of the assets, liabilities, financial condition, and contribution rate of the retirement system, upon information supplied by the department.

  (3) The retirement board and the department shall conduct and review an experience investigation study and adopt risk assumptions on which actuarial valuations are to be based, after consultation with the actuary, and the state treasurer. The experience investigation study must be periodically reviewed at least once every 5 years.

  (4) Every April 1 following a periodic review of risk assumptions under subsection (3), the office of retirement services on behalf of the department and the state treasurer shall collaborate to submit a report to the senate majority leader, the speaker of the house of representatives, the senate and house of representatives appropriations committees, the senate and house fiscal agencies, and the department of state police. A report required under this subsection must be published on the office of retirement services’s website and include at least all of the following:

  (a) Forecasted rate of return on investments at all of the following probability levels:

  (i) 5%.

  (ii) 25%.

  (iii) 50%

  (iv) 75%.

  (v) 95%.

  (b) The actual rate of return on investments for 10-, 15-, and 20-year time intervals.

  (c) Mortality assumptions.

  (d) Retirement age assumptions.

  (e) Payroll growth assumptions.

  (f) Any other assumptions that have a material impact on the financial status of the retirement system.