Before issuing any bonds the board shall pass a formal resolution in which shall be found and declared (1) the total amount of the tax as confirmed (both by the original and the supplemented assessment, if any), (2) the total amount of the deductions, if any, thereon, (3) the estimated cost of collection, and (4) the total amount of the net tax available for the payment of the principal and the interest of the bonds the district intends to issue.