721—21.600 (43) Primary election signatures—plan three supervisor candidates. The minimum number of signatures needed by candidates for the office of county supervisor elected under plan three, where candidates are voted upon only by the voters of the supervisor district, shall be determined by one of the two following methods.
	 21.600(1) If there were 5,000 or more votes cast in the supervisor district for a political party’s candidate for governor or for president of the United States, the minimum number of signatures needed is 100.
	 21.600(2) If there were less than 5,000 votes cast in the supervisor district for a political party’s candidate for governor or for president of the United States, the minimum number of signatures is determined by using one of the following formulas:
Democratic candidate’s signature requirement: ([AD ÷ S] + VD) × .02
Republican candidate’s signature requirement: ([AR ÷ S] + VR) × .02

AD	=	the number of absentee votes received in the entire county by the Democratic party’s candidate for governor or for president of the United States in the previous general election.	
AR	=	the number of absentee votes received in the entire county by the Republican party’s candidate for governor or for president of the United States in the previous general election.	
S	=	the number of supervisor districts in the county (3 or 5).	
VD	=	the number of votes cast in the supervisor district for the Democratic party’s candidate for governor or for president of the United States in the previous general election. (If this number is 5,000 or more, the minimum number of signatures needed is 100.)	
VR	=	the number of votes cast in the supervisor district for the Republican party’s candidate for governor or for president of the United States in the previous general election. (If this number is 5,000 or more, the minimum number of signatures needed is 100.)	
This rule is intended to implement Iowa Code section 43.20(1)“d.”