(b) The commission shall prepare a written report on the costs of programs and activities conducted by each electrical corporation and gas corporation that is subject to this section, including activities conducted to comply with their duty to serve. The report shall be completed on an annual basis before April 1 of each year, and shall identify, clearly and concisely, all of the following:

1. (1) Each program mandated by statute and its annual cost to ratepayers.
2. (2) Each program mandated by the commission and its annual cost to ratepayers.
3. (3) Energy purchase contract costs and bond-related costs incurred pursuant to Division 27 (commencing with Section 80000) of the Water Code.
4. (4) All other aggregated categories of costs currently recovered in retail rates as determined by the commission.