(b) The county treasurer shall, at least quarterly, apportion any interest or other increment derived from the investment of funds pursuant to this section in an amount proportionate to the average daily balance of the amounts deposited by the local agency and to the total average daily balance of deposits in the investment pool. In apportioning and distributing that interest or increment, the county treasurer may use the cash method, the accrual method, or any other method in accordance with generally accepted accounting principles.

Prior to distributing that interest or increment, the county treasurer may deduct the actual costs incurred by the county in administering this section in proportion to the average daily balance of the amounts deposited by the local agency and to the total average daily balance of deposits in the investment pool.