(1) Except as provided in subsection (2), the eighteenth judicial circuit consists of the county of Bay and has 3 judges.

  (2) Beginning on the earlier of the following dates, the eighteenth judicial circuit has 2 judges:

  (a) The date on which a vacancy occurs in the office of circuit judge in the eighteenth judicial circuit.

  (b) The beginning date of the term for which an incumbent circuit judge in the eighteenth judicial circuit no longer seeks election or reelection to that office.