Okla. Stat. tit. 17, § 160.2

All existing trusts subject to this act shall submit information, within ninety (90) days after the effective date of this act, showing the rate being charged, along with a complete financial statement, including the names of all trustees, officers, employees and beneficiaries. The Commission shall determine the reasonableness of such rates, in line with the criteria used in nontrust utilities, and enter appropriate orders by December 31, 1975, to establish the rates that shall be charged by trusts, authorities, companies, persons and entities covered by the provisions of this act. Laws 1975, c. 291, § 2, emerg. eff. June 5, 1975.