The retirement board shall submit to the governor for transmittal to the general assembly, on or before the first day of December in each year, an annual report showing the financial transactions of the system for the fiscal year next preceding that date. The report shall contain among other things, a financial balance sheet as of the end of that year, a statement of income and expenditures, a valuation balance sheet as prepared by the actuary, a detailed statement of investments acquired and disposed of during the year, and any other statistical data that are deemed necessary for a proper interpretation of the condition of the system and the results of its operations. The report shall also embody any other data that may be of use in the advancement of knowledge concerning employee pensions of the participating municipalities, and any recommendations of the board for changes in the laws pertaining to the system.