In order to carry out the purposes, powers and duties of the City Government established by this Charter, the City shall have the power to assess taxes and to lay and collect rents, tolls and excises.  The annual general ad valorem tax levy for municipal purposes shall not exceed one and one half (1-1/2) percent (15 mills) of the State Equalized Valuation of all real and personal property in the City.  The City taxes shall be levied and collected in a manner provided by the general tax laws of the State or by this Charter.