641—75.3 (255A) Quota assignment. The department of public health shall establish the quota annually for each county. The formula used shall be based upon, but not limited to, the following criteria:
	  1. 	 Dollars available to the program.
	  2. 	 Average number of births for the most recent three-year period for each county.
	  3. 	 Per capita income for each county.