Sec. 8. DEPLETION OF FUND; REDUCTION OF BENEFITS. In the event the Pension System Fund becomes seriously depleted, in the opinion of the Pension Board, said Pension Board may proportionately and temporarily reduce the benefits of all pensioners and beneficiaries, but such reduction of benefits shall continue only for such time as such depleted condition continues to exist, and after such time of depletion has ceased to exist and the Pension Board finds said Pension System Fund is in condition to warrant, it shall thereafter restore the benefits and resume payment of all pensioners and beneficiaries as though such preceding reductions had not occurred.