The city shall have power through its Council to levy and collect annually a property tax for the payment of outstanding warrants and also for the purpose of providing funds for the payment of interest on, and for the creation of sinking funds for all outstanding bonded indebtedness, and in addition thereto, the city shall have the power to levy and collect annual taxes for the payment of current expenses not exceeding eighteen mills on the dollar of assessed valuation. In addition to the levy above provided for the city may levy annually such necessary amount as provided by law, for Library purposes, one mill for Park purposes and one-half mill for Publicity purposes to advertise and exploit the advantages of the city and to promote its growth in population and new industries. The usage and system now in force of having a “Current Expense Fund” in the administration of the financial affairs of the city is preserved and continued in force and carried forward into this Charter and the system is hereby established under this Charter; accordingly there shall be maintained a fund designated as the “Current Expense Fund”. All moneys collected from taxes and licenses shall be paid into the “Current Expense Fund”. Warrants drawn on the “Current Expense Fund” shall continue to be issued and paid in numerical order as heretofore.