The county trustee of any county in which a drainage district has been organized under the laws of this state shall make monthly settlement with the county mayor of the county in which the district was organized, showing the drainage assessments collected during the month, giving date collected, tract number, name of owner, for what years assessments are paid, amount of assessments, interest and penalty, amount paid in cash, amount paid in bonds, coupons, or credit memorandums, and amount of credit memorandums issued during the month and still outstanding and to whom issued. The settlement shall also show what bonds, coupons or credit memorandums were received during the month in settlement of assessments and the date same were cancelled by the trustee. The settlement shall be filed with the county mayor as provided in this section, together with all cancelled bonds, coupons and credit memorandums, taking the county mayor's receipt for the settlement and, when approved by the county mayor, shall be copied on the drainage record book in the county clerk's office.