The memorial district tax levied in any one year shall not exceed the rate of three-tenths of one cent ($0.003) on each dollar ($1) of the assessed valuation of all taxable property in the district, exclusive of any tax which may be required to pay the principal of and interest upon any bonded indebtedness of the district. In no event shall the tax exceed an amount that is sufficient to pay the estimated expenses of operating and maintaining the memorial district for the next year and the estimated capital outlay of the district for the next two years.