Sec. 3. SALARIES IN COUNTIES HAVING ENUMERATED POPULATION. In all counties of the state of Texas having a population of not less than sixteen thousand five hundred fifty (16,550) nor more than sixteen thousand six hundred (16,600) according to the last United States Federal Census, the salary of the County Superintendent of Public Instruction shall be fixed by order of the County Board of Education in and for such counties at an amount not less than Eighteen Hundred ($1800.00) Dollars per year nor more than Two Thousand Two Hundred and Fifty ($2,250.00) Dollars per year, and said salary shall be exclusive of any and all traveling expenses allowed by law; and in all counties having a population of not less than seventeen thousand five hundred sixty-five (17,565) nor more than seventeen thousand six hundred (17,600) according to the last preceding Federal Census, the salary of the County Superintendent of Public Instruction shall be fixed by order of the County Board of Education in and for such counties at an amount not less than Nineteen Hundred ($1900.00) Dollars per year nor more than Two Thousand Two Hundred and Fifty ($2,250.00) Dollars per year, and said salary shall be exclusive of any and all traveling expenses allowed by law.