Any faculty member who has the qualifications necessary for the next higher classification as hereinbefore set forth, shall, commencing with the next succeeding regular college year, within the percentage limitation prescribed by this act, receive the compensation prescribed for such advanced classification which shall be at least one (1) additional increment in the higher salary range in excess of the increment earned by him during the previous year when recommended by the president of the college and approved by the board of trustees.
24 P.S. § 1864.5