At the time of making its annual budget and tax levy, the city shall provide for the levying of a sum sufficient, with the other resources of the fund, to pay warrants so issued during the preceding fiscal year; provided, that such warrants shall at no time exceed five percent of the outstanding bond obligations guaranteed by the fund. As among the several issues of bonds or warrants guaranteed by the fund, no preference shall exist, but defaulted interest coupons, bonds and warrants shall be purchased out of the fund in the order of their presentation. (Ord. 1337, §28, 1980).