105 ILCS 5/34-29
The board shall for each fiscal year and may as often as necessary, appoint certified public accountants to examine the business methods and audit the accounts of the board as of December 31, 1972, as of December 31, 1973, as of August 31, 1974, as of August 31 of each year thereafter through August 31, 1996, as of June 30, 1997, and as of June 30 of each year thereafter, and a report thereof, together with any recommendations of such accountants as to changes in business methods of the board or any of its departments, officers or employees shall be made to the mayor, the city council, and the board and be filed in the records of the board. The board shall prepare and publish an annual report including in detail all receipts and expenditures, specifying the source of the receipts and the objects of the expenditures, and shall transmit it to the mayor and the city council. The board shall account for the expenses of each fiscal year but shall not be required to make any apportionment of such expenses between the two separate levies made during each calendar year.
105 ILCS 5/34-29