(8) "Rural area" means any county having a population of less than 35,000 according to the United States decennial census of 1990 or any future such census.

(11) "Rural area" means a county with a population density of no greater than 65 persons per square mile, as defined by the United States decennial census of 1990.

(3) "Rural area" means any area within this state which is located outside:

(21) "Rural area" means any nonurban area in the state as defined in rules and regulations of the department.