If the corporate authorities determine that excess revenues exist in a special service area fund at the end of the life of the special service area and if the option to abate a portion of the final tax levy for the special service area is no longer available, then the excess funds must be refunded to the taxpayers of record for all parcels within the special service area, as of the date the refund is declared, on a pro rata basis based upon each parcel’s proportionate share of the total equalized assessed valuation of all parcels within the special service area. In processing the refund, the county or municipality may deduct not more than 5% of the amount declared to be refunded to cover its costs and expenses relative to declaring and making the refund.