Each member of the Commission shall take the oath required by Article I, § 9 of the Maryland Constitution. Each regional member of the Commission serves for a term of 5 years and until his successor is appointed and qualifies. The terms of these members shall be staggered as required by prior appointments, three of which were made for a 1–year term beginning June 1, 1959, three of which were made for a 2–year term beginning June 1, 1959, and one of which was made for a 4–year term beginning June 1, 1969. A member appointed to fill a vacancy in an unexpired term serves only for the remainder of that term. A regional member of the Commission is entitled to the compensation provided in the State budget, but in no event may compensation exceed $10,000 per member annually.