Every year beginning with the year 1976, the actuary shall make an actuarial investigation into the mortality, service, and compensation experience of the members and beneficiaries of the retirement system, and shall make a valuation of the assets and liabilities of the system, and, taking into account the result of the investigation and valuation, the retirement board shall:
(1) Adopt for the retirement system such mortality, service, and other tables as shall be deemed necessary; and
(2) Certify the rates of contribution payable by the state of Rhode Island to carry out the provisions of chapters 8 — 10 of this title in accordance with the provisions of § 36-10-2.