Sec. 2. For municipal retirement systems created after August 31, 1981, through charter, ordinance, or statute, benefits shall be ascertained by the system's actuary in relationship to contributions. The level of benefits shall never be in excess of the amount actuarially determined for the system to be financially sound. An actuary hired by a retirement system shall have at least five years of experience working with one or more public retirement systems and be a fellow of the Society of Actuaries, a member of the American Academy of Actuaries, or an enrolled actuary under the federal Employees Retirement Security Act of 1974.