The actuary shall recommend such data as shall be necessary for actuarial valuation of the various funds created by this act. Once in every 3-year period the actuary shall make an actuarial investigation into the mortality, service and salary experience of the members and beneficiaries and shall make a valuation of the assets and liabilities of the various funds created by this act. Upon the basis of such investigation and valuation, with the advice of the actuary, the commission shall adopt for the retirement system such mortality, service and other tables as shall be deemed necessary.
N.J.S. § 43:6A-31