2.124.360   Sources from which payments to be made.
   All payments provided hereunder to or on account of persons who are members under this article shall be made from funds derived from the following sources, plus interest earned on such funds:
   A.   The normal rate of contribution of each member under this article shall be based on his or her nearest age at the effective date of his or her membership in the retirement system. The normal rate of contribution of each such member, to be effective from the effective date of membership under such section shall be such as, on the average for such member, will provide, assuming service without interruption under this article, one-half of that portion of the service retirement allowance to which he or she would be entitled if retired at age sixty (60). The normal rate established for age fifty-nine (59) shall be the rate for any member who has attained a greater age before entrance into the system, and that established for age twenty (20) shall be the rate for any member who enters the system at a lesser age. Members' normal rates of contribution shall be changed by the board on the basis of periodical actuarial valuations and investigations. No adjustment shall be included in members' normal rates because of time during which members have contributed at different rates.
   B.   There shall be deducted from each payment of compensation made to a member under this article a sum determined by applying the member's normal rate of contribution to such compensation. The sum so deducted shall be paid forthwith to the retirement system. Such contribution shall be credited to the individual account of the member from whose salary it was deducted and the total of such contributions, together with interest credited thereon in the same manner as is prescribed by this chapter for crediting interest to contributions of other members of the retirement system, shall be applied to provide part of the retirement allowance granted to such member or his or her estate or beneficiary as provided in Sections 2.124.320 and 2.124.340 of this chapter.
   C.   Contributions based on time included in subsections A and C of Section 2.124.350 of this chapter and deducted prior to July 1, 1953, from compensation of persons who become members under former (1970) Charter Section 175.1 and standing with interest thereon, to the credit of such members on the records of the retirement system on such date, shall continue to be credited to the individual accounts of such members and shall be combined with and administered in the same manner as the contributions deducted after such date.
   D.   The total contributions, with interest thereon, made by or charged against the city and standing to its credit, on July 1, 1953, in the accounts of the retirement system on account of persons who became members on such date under former (1970) Charter Section 175.1, shall be applied to provide the benefits hereunder for or on account of them.
   E.   The city shall contribute to the retirement system such amounts as may be necessary, when added to the contributions referred to in the preceding paragraphs of this section, to provide the benefits payable to or on account of persons who are members under this article. Such contributions of the city to provide the portion of the benefits hereunder which shall be based on service rendered by each member prior to the date upon which his or her rate of contribution is determined in subsection A of this section, shall not be less during any fiscal year than the amount of such benefits paid during such year. Such contributions of the city to provide the portion of the benefits hereunder which shall be based on service rendered by respective members on and after the date stated in the next preceding sentence shall be made in annual installments and the installment to be paid in any year shall be determined by the application of a percentage to the total salaries paid during such year to persons who are members under this article, such percentage to be the ratio of the value at the effective date hereof or at the date of the last valuation prior to such date or at the later date of a periodical actuarial valuation and investigation into the experience under the system of the benefits thereafter to be paid to or on account of persons who are members under this article, from contributions of the city, less the amount of such contributions and plus accumulated interest thereon then held by such system to provide such benefits on account of service rendered by respective members after the date stated in the sentence next preceding, to the value at such respective dates of salaries thereafter payable to such members. Such values shall be determined by the actuary, who shall take into account the interest which shall be earned on such contributions, the compensation experience of members and the probabilities of separation by all causes of members from service before retirement and of death after retirement. Such percentage shall be changed by the board on the basis of such values determined in such periodical actuarial valuation and investigation into the experience under the system. Nothing in this subsection, however, shall prevent the calculation and use under the system in the manner described for the percentage under this subsection, of one percentage relating to all persons who are members under this article and Article IV of this chapter, and to be applied to the total compensation paid during the respective year to such persons, for the determination of the city's contribution to the retirement system, with substantially the same effect as if separate percentages had been calculated under the respective articles. The percentage to be used under such two articles shall be the percentage which has been previously adopted by the board and is being applied on the effective date of this chapter. Such percentage shall remain in effect until redetermined by the board on the basis of the periodical investigation and actuarial valuation under the system and the contributions resulting from its use shall be applied to provide part of the benefits under both of such articles, without segregation according to article.
   F.   To promote the stability of the retirement system through a joint participation in the result of variations in the experience under mortality, investment and other contingencies, the contributions of both members and the city held by the system to provide the benefits for or on account of persons who are members under this article shall be a part of the fund in which all other assets of such system are included. Nothing in this section shall affect the obligations of the city to pay to the retirement system any amounts which may be or become due under the provisions of the Charter prior to July 1, 1953, and which are represented on such date in the accounts of such system by debits against the city. (Prior code § 34.03.310)