The state salaries for the several categories of school employees shall be in accordance with salary schedules set forth in this title except that no such schedule shall prevent a school district from increasing those salaries by the amount of a supplement appropriately provided by the local school district including Division III state funds, and from funds other than those appropriated by this State.
14 Del. C. 1953, § 1093; 56 Del. Laws, c. 292, § 6.