50955. (a) The board shall, from time to time, determine and fix the annual interest rate and actuarial interest rate.(b) The board shall keep in convenient form the data necessary for the actuarial valuation of the award system. The board shall, at least quadrennially, cause to be made an actuarial investigation into the mortality and service experience of members and persons receiving awards and an actuarial valuation of the assets and liabilities of the award system.(c) When there is insufficient data upon which to establish mortality rates or other actuarial assumptions required to evaluate the obligations of the award system, the board may adopt appropriate assumptions that, upon the advice and recommendation of the actuary, are necessary.(Repealed and added by Stats. 2007, Ch. 651, Sec. 2. Effective January 1, 2008. Operative March 1, 2008, by Section 50979.)