Section 10
SEC. 10. Sinking Fund.&mdashThere shall be established a sinking fund in such a manner that the annual contribution thereto, accrued at such rate of interest as may be determined by the Secretary of Finance in consultation with the Monetary Board, shall be sufficient to redeem at maturity the bonds issued under this Act. The Central Bank of the Philippines shall keep said fund in custody and shall invest the same in such manner as the Monetary Board may approve, charging all expenses of such investment and crediting interest or other earnings thereon and other income belonging to the said sinking fund. Provided,That administrative expenditures of the Central Bank, while administering the fund of the Agency, shall be chargeable against the earnings of the fund:And provided, further,That fees charged shall be based on the percentage earnings of the interests.