Accounts shall be kept for each public utility owned or operated by the City, in such manner as to show the true and complete financial results of such City ownership and operation, including all assets and all liabilities, appropriately subdivided by classes, depreciation reserve, other reserves and surplus; also revenues, operating expenses including depreciation, interest payments, rental, and other disposition of annual income. The accounts shall show actual capital cost to the City of each public utility owned, also the cost of all extensions, additions, and improvements and the source of funds expended for such capital purposes. They shall show as nearly as possible the cost of any service furnished to or rendered by any such utility to any City Government Department. The City Council shall cause an annual report to be made by a Certified Public Accountant and shall publish such report showing the financial results of such City ownership and operation, giving the information specified in this section and such other data as the City Council shall deem expedient.