The administration of the system is hereby vested in the board of trustees created in RCW 41.44.070 of this chapter and the board shall:

(1) Keep in convenient form such data as shall be deemed necessary for actuarial valuation purposes;

(2) From time to time, through its actuary, make an actuarial investigation into the mortality and service experience of the beneficiaries under this chapter and the various accounts created for the purpose of showing the financial status of the retirement fund;

(3) Adopt for the retirement system the mortality tables and such other tables as shall be deemed necessary;

(4) Certify annually the amount of appropriation which each city shall pay into the retirement fund in the next fiscal year, at such a time that the local authorities shall have ample opportunity for including such expense in the budget;

(5) Keep a record of all its proceedings, which shall be open to inspection by the public;

(6) From time to time adopt such rules and regulations not inconsistent with this chapter, for the administration of the provisions of this chapter, for the administration of the fund created by this chapter and the several accounts thereof, and for the transaction of the business of the board;

(7) Provide for investment, reinvestment, deposit, and withdrawal of funds;

(8) Prepare and publish annually a financial statement showing the condition of the fund and the various accounts thereof, and setting forth such other facts, recommendations, and data as may be of use in the advancement of knowledge concerning the statewide city employees retirement system, and furnish a copy thereof to each city which has joined the retirement system, and to such members as may request copies thereof;

(9) Serve without compensation but shall be reimbursed for expense incident to service as individual members thereof;

(10) Determine equitable amount of administrative expense and death-in-line-of-duty benefit expense to be borne by each city;

(11) Make available to any city considering participation in the system, the services of the actuary employed by the board for the purpose of ascertaining the probable cost of such participation. The cost of any such calculation or valuation shall be paid by the city requesting same to the retirement system;

(12) Perform such other functions as are required for the execution of the provisions of this chapter;

(13) No member of the board shall be liable for the negligence, default, or failure of any employee or of any other member of the board to perform the duties of his or her office and no member of the board shall be considered or held to be an insurer of the funds or assets of the retirement system but shall be liable only for his or her own personal default or individual failure to perform his or her duties as such member and to exercise reasonable diligence to provide for the safeguarding of the funds and assets of the system;

(14) Fix the amount of interest to be credited at a rate which shall be based upon the net annual earnings of the fund for the preceding twelve-month period and from time to time make any necessary changes in such rate;

(15) Distribute excess interest income to retired members on a cost of living index basis, as published by the United States department of health, education, and welfare, applied only to the annuity and current service portion of the retired members' retirement allowance: PROVIDED, That such distribution shall not exceed the income earned and received on open end investments.