1. Except in counties where the board of county commissioners is the board of hospital trustees, the board of hospital trustees for the public hospital consists of five trustees, who must:
(a) Be residents of the county or counties concerned.
(b) Be registered to vote in the county or counties concerned.
(c) Be elected as provided in subsection 2.
2. In any county:
(a) Whose population is less than 100,000, hospital trustees must be elected for terms of 4 years in the same manner as other county officers are elected.
(b) Whose population is 100,000 or more but less than 700,000, hospital trustees must be elected from the county at large for terms of 4 years.