(a) There is hereby assessed a sufficient percentum of the salary from each employee's pay so as to adequately maintain the pension fund hereby created, but in no event shall said assessment exceed five (5) percent of the monthly salary of each employee. Within such limit, the percentum of salary so withheld shall be fixed annually by the board of commissioners, and same shall be paid into the pension fund in cash and held by the treasurer subject to the order of the board of trustees.
(b) The board of commissioners shall annually levy a tax not exceeding five cents ($0.05) on each one hundred dollars ($100.00) valuation of taxable property in the city, and the proceeds of such tax shall be paid into the pension fund in cash and held by the treasurer subject to the order of the board of trustees. In no year shall the contribution of the city by means of such tax be less than the total amount assessed upon and deducted from the salary of the employees.