(a) Beginning with the 1999 calendar year, each electric utility shall file a report with the commission not later than 90 days after the end of each year during the freeze period under a schedule and a format determined by the commission.
(b) The report shall identify any positive difference between annual revenues, reduced by the amount of annual revenues under Sections 36.203 and 36.205, the revenues received under the interutility billing process as adopted by the commission to implement Sections 35.004, 35.006, and 35.007, revenues associated with transition charges as defined by Section 39.302, and annual costs.