Section 40 ILCS 5/11-210 - Investment and interest reserve(1) Gains from investments and interest earnings shall be credited to this reserve. Losses from investments shall be charged to it. From this reserve shall be transferred amounts due in interest upon balances existing in other reserves of this fund.(2) Amounts necessary according to the American Experience Table of Mortality and interest at the rate of 4% per annum or the Combined Annuity Mortality Table and interest at the rate of 3% per annum, as to those assets or liabilities to which either table may be applicable in accordance with the provisions of this Article, to make the annuity payment reserve equal to its liabilities (including the present values of all annuities entered upon, or fixed and not entered upon, chargeable to such reserve) shall be transferred to the annuity payment reserve at least once each year.(3) That portion of the annual investment earnings on the fund's invested assets exclusive of gains or losses on sales or exchanges of assets during the year on the fund's invested assets, as specified in Section 11-134.3 of this Article, shall be transferred from the investment and interest reserve to the Supplementary Payment Reserve set forth in said Section 11-134.3. Any balance in the investment and interest reserve shall be either charged or credited to the Prior Service Annuity Reserve depending on whether a deficiency or surplus exists in said investment and interest reserve.