The following annual salaries shall be paid in monthly installments, namely: Mayor $1,200.00; Treasurer $3,000.00, Comptroller, $3,000.00. All appointive officers shall receive such salary as may be fixed by the Council by ordinance. Provided, that at intervals of not less than two years, the salaries of these officers may be increased by ordinance, proportionate with the increase in the city in population, to be ascertained by the Council, but no officer shall receive the benefit of any increase in salary of his office during the period of his incumbency. The members of the City Council shall receive such salaries as may be fixed by the City Council by ordinance not exceeding $300.00 per year, provided, that deduction of Five ($5.00) Dollars for each absence shall be made from the salary of each member of the City Council who, shall be absent from any regular meeting of the city Council. The salary or compensation of no officer of such city shall be increased or diminished during his term of office, nor shall any such officer be allowed an extra or additional compensation, either directly or indirectly for the rendition of services that the City Council has the power to require such officer to perform by virtue of his office. The salaries of all city officers shall be payable monthly.