(a) (1) The commission shall audit the books and records for regulatory purposes of every electrical, gas, heat, telegraph, telephone, and water corporation serving over 10,000 customers at least once every three years or in accordance with the commission-approved general rate case cycle, if that cycle provides for a rate case no less frequently than once every five years.
(2) The commission shall review or audit the books and records for regulatory purposes of every electrical, gas, heat, telegraph, telephone, and water corporation serving 10,000 or fewer customers at least once every five years.
(b) An audit conducted in connection with a rate proceeding shall be deemed to fulfill the requirements of paragraph (1) of subdivision (a), and a review or audit conducted in connection with a rate proceeding shall be deemed to fulfill the requirements of paragraph (2) of subdivision (a).
(c) The commission shall post reports of reviews and audits and other pertinent information on its internet website.