Be it further enacted, That each budget shall include (a) a statement showing in parallel columns for each source the amount of revenue collected in the last preceding fiscal year, estimated revenue for the current fiscal year, and estimated revenue for the ensuing fiscal year, and (b) a statement showing in parallel columns expenditures and encumbrances in the preceding fiscal year, appropriations and estimated expenditures or encumbrances for the current fiscal year, and proposed appropriations for the ensuing fiscal year, with such data broken down by departments and agencies according to the accounting classification used by the city. In justification of proposed appropriations for the ensuing fiscal year, the city manager may include work programs unit costs, and other information in addition to the information as herein required, and he shall furnish such other additional information as may be required by the council. The budgets as submitted by the city manager shall be accompanied by a message from him containing a statement of general fiscal policies of the city, the important features of the budgets, explanations of major changes proposed for the ensuing fiscal year as compared with the preceding and current fiscal years, a general summary of the budgets, and such other comments and information as he may deem pertinent. The city manager may recommend and estimate the yield from now sources of revenue, provided such estimates are separated clearly from estimates of revenue from existing sources.