County boards of education may permit the use of school bus equipment for transportation in connection with athletic events, boy’s and girl’s clubs, special events in connection with the schools, official functions by the office of the Adjutant General of South Carolina, and the Reserve Components of the United States Armed Forces which must reimburse the boards of education, at least, for the costs of use of the buses, including depreciation, and other educational purposes as may appear proper to the respective boards.