The initial appointment of members serving on the Penn Square Commission shall consist of three members appointed for a term of one year, two of whom shall be representatives of the Chamber of Commerce of Reading and Berks County and Downtown Association of Reading Endeavors; two members appointed for a term of two years; and two members appointed for a term of three years. Thereafter, the representatives from the Chamber of Commerce of Reading and Berks County shall be appointed on an annual basis for one year and the remaining 10 members shall be appointed for a term of two years and shall serve until their successors are appointed. Any vacancy occurring other than by expiration of term shall be filled by appointment for the unexpired term in the manner as provided herein for original appointments.