Section 2
SEC. 2. For the purpose of determining the amount of annuity which a retired employee shall receive the following classifications and rates shall be established upon the basis of the annuity consisting of a fractional part of the average pay, salary or compensation, for the three years of service rendered prior to the granting of the pension with maximum average pay, salary or compensation in no case exceeding four thousand pesos per annum. The annual annuity as computed under this Act shall be four-tenths of the aver- age salary for twenty years of service; five-tenths of the average salary for twenty-three years of service; six-tenths of the average salary for twenty-six years of service; seven-tenths of the average salary for twenty-nine years of service; eight-tenths of the average salary for thirty-two or more years of service.