As used in this Act, the term “resident circuit judge” or “resident judge” refers to a circuit judge who, immediately prior to July 1, 1971, was an associate judge and who became a circuit judge on July 1, 1971 by reason of paragraph (a) of Section 4 of the Transition Schedule of the Constitution of 1970 or a circuit judge who was appointed after June 30, 1971 by the Supreme Court to fill the vacancy existing prior to July 1, 1971 in the office of a former associate judge and whose office was, prior to July 1, 1971, filled by election from a single county or, in the case of Cook County, from one of the 2 units of the county, and not from the circuit at large.