(a) The board shall have kept a complete book of accounts for the district.
(b) On June 1 of each year, the board shall select a competent auditor to examine the accounts, books, and reports of the depository, the tax assessor-collector, and the board.
(c) The auditor shall make a full report and file a copy of the report with the depository, the county clerk, and the board.
(d) The report must state the purposes for which money from each fund was spent.