55 ILCS 5/3-11013

The county treasurer shall make to the county clerk an annual report, under oath, of all interest received by the county treasurer or credited to the county treasurer by any bank, savings and loan association, savings bank, or credit union, in which is deposited any county moneys, and at the time of making such report the county treasurer shall pay into the county treasury for the benefit of the county the aggregate amount of all interest so received by or credited to him, as shown by said report. Such report shall show the name of each bank or depository where any county moneys are deposited.