If the board determines that the funds derived from the sources provided for in this chapter are not actuarially sufficient at any time to enable the board to pay in full each person determined to be entitled to the benefits provided for, plus all contingent and other liabilities, then a prorated percentage of such payments shall be made to each person entitled thereto until the funds shall be replenished actuarially sufficiently to enable the board to resume such payments in accordance with the terms of this chapter. In no event shall the board or any member thereof be liable to any person for any deficiency in payments made under this Code section.