519

The expense fund shall be the fund from which the expense of the administration of the retirement system shall be paid exclusive of amounts payable as retirement allowances and as other benefits provided herein. Contributions shall be made to the expense fund as follows: 1. The retirement board shall determine the amount required to defray the expenses allocated to those functions which directly or indirectly affect the system's investment operations. This amount so determined shall be collected from net investment income which shall include but not be limited to interest, dividends, and realized gains and losses. 2. The retirement board shall determine annually the amount required to defray the remaining estimated expenses in the ensuing fiscal year and shall certify such amount to the commissioner of education who shall apportion to each employer a proportionate part thereof as provided under subdivision two of section five hundred twenty-one. Each employer shall make payment for the amount so apportioned to him in the same way as he shall make other payments provided for by this article.