The treasurer of the board of managers shall have the custody of all money and property received in trust by the board of managers and shall pay out that money or property only upon the written order of the board, signed by at least 2 of the board members. The treasurer shall keep permanent books of record of all trust funds, all receipts and disbursements of trust funds, and the purposes of all receipts and disbursements. The treasurer shall annually make a report in writing to the board of managers, under oath, showing balances, receipts, and disbursements and including a statement showing the amount and principal of trust funds on hand and how invested. The report shall be audited by the board and, if found correct, shall be transmitted to the township collector at the same time that the treasurer of a village is required by law to make his or her report, to be approved and preserved in the same manner if found to be correct.