In counties with a population of not less than nine thousand and seventy (9,070) nor more than nine thousand, two hundred (9,200), as shown by the Federal Census of 1940, the county board of trustees may make such provisions as they deem necessary for traveling expenses of the ex officio county superintendent or any assistant he may have, provided that the amount of the traveling expenses shall not exceed the sum of Six Hundred Dollars ($600) per annum. The amount of such expenses so allowed shall be paid in the manner and in accordance with now existing laws governing the maintenance of the office of the ex officio county superintendent.