(1) Such authority or officer shall cause to be deducted from the compensation of each member, on each and every payroll of such employer for each and every payroll period, the percentage of earnable compensation applicable to such member.
(2) To facilitate the making of deductions, the authority or officer may modify the deduction required of any member by such an amount as shall not exceed one tenth of one percent (0.1%) of the annual earnable compensation upon the basis of which such deduction is made.