The board of directors of the joint underwriting association shall engage the services of an independent actuarial firm to develop and recommend actuarially sound rates, rating plans, rating rules and classifications. The Director of the Department of Consumer and Business Services shall approve rates filed by the joint underwriting association in accordance with ORS § 737.310. All rates approved for the joint underwriting association shall be actuarially sound and calculated to be self-supporting. [1987 c.774 § 79]