The commissioner of revenue is the fiduciary of the trust fund and shall invest the fund to provide increasing returns from capital appreciation and net income over long-term periods to the fund's current beneficiaries. The commissioner may invest the money in the fund on the basis of probable total rate of return to promote the long-term generation of capital appreciation and income. In managing the trust fund, the commissioner shall
(1) consider the status of the fund's capital and the income generated on both a current and a probable future basis;
(2) determine the appropriate investment objectives;
(3) establish investment policies to achieve the objectives; and
(4) act only in regard to the financial interests of the fund's beneficiaries.