70 ILCS 1830/33

After the expiration of initial terms, such successor shall hold office for the term of 3 years beginning the first day of July of the year in which the term of office commences. In the case of a vacancy during the term of office of any member, the Governor shall make an appointment for the remainder of the term vacant and until a successor is appointed and qualified. No more than 8 members of the Board may be affiliated with the same political party at the time of appointment.