The board of supervisors of any county issuing refunding bonds under the provisions of Sections 65-33-61 through 65-33-65, shall levy an annual tax of not less than five mills on each dollar of the assessed valuation of taxable property within such county for the purpose of providing funds sufficient to pay such bonds at maturity and interest thereon as it accrues. The said tax shall be levied and collected as other county taxes are levied and collected, and the proceeds thereof shall be remitted by the county tax collector to the State Treasury at the time when state taxes are required by law to be so remitted. The State Treasurer shall credit the amount to the interest and sinking fund referred to in Section 65-33-65. On or before October 1st in each year, the State Treasurer shall certify to the board of supervisors of each such county the amount standing to the credit of such interest and sinking fund as of September 15th, of that year, and if such amount shall be sufficient (1) to pay all principal of and interest on such bonds then due and owing and (2) all principal of and interest on such refunding bonds maturing and accruing during the period of twelve months running from said September 15th, then and in that event such board of supervisors may reduce the aforesaid taxes or omit the same for the ensuing year, as such board may determine. All funds paid into the State Treasury hereunder shall remain in the State Treasury for the payment of principal and interest on such refunding bonds until all the principal and interest on such refunding bonds shall have been fully paid.