Class B.—All persons receiving an annual salary of $720 or more, or a compensation at the rate of $720 or more, but less than $840 per annum.
Class C.—All persons receiving an annual salary of $840 or more, or a compensation at the rate of $840 or more, but less than $900 per annum.
Class D.—All persons receiving an annual salary of $900 or more, or a compensation at the rate of $900 or more, but less than $1,000 per annum.
Class E.—All persons receiving an annual salary of $1,000 or more, or a compensation at the rate of $1,000 or more, but less than $1,200 per annum.
Class 1.—All persons receiving an annual salary of $1,200 or more, or a compensation at the rate of $1,200 or more, but less than $1,400 per annum.
Class 2.—All persons receiving an annual salary of $1,400 or more, or a compensation at the rate of $1,400 or more, but less than $1,600 per annum.
Class 3.—All persons receiving an annual salary of $1,600 or more, or a compensation at the rate of $1,600 or more, but less than $1,800 per annum.
Class 4.—All persons receiving an annual salary of $1,800 or more, or a compensation at the rate of $1,800 or more, but less than $2,000 per annum.
Class 5.—All persons receiving an annual salary of $2,000 or more, or a compensation at the rate of $2,000 or more, but less than $2,500 per annum.
Class 6.—All persons receiving an annual salary of $2,500 or more, or a compensation at the rate of $2,500 or more per annum.