On or before the first Monday in May of each year, the board of trustees of the sinking fund shall certify to the board of county commissioners the rate of tax necessary to provide a sinking fund for the payment, at maturity, of bonds issued by the county prior to August 17, 1921, and for the payment of interest on said bonded indebtedness. The amount so certified shall be set forth in the annual budget of the board of county commissioners, without diminution.
R.C. §327.08