Ariz. Rev. Stat. § 15-975
In determining the amount of state, county and federal monies or school aid payable to a joint common school district, the portion of the territory of the joint common school district within each county shall be regarded as a separate school district lying within such county. Records of student count shall be kept as to make readily ascertainable the attendance of pupils residing in the portion of the school district in each county. The forms and reports required by law to be filed shall be appropriately filed. Student enrollment and attendance information required by this subsection shall be submitted electronically to the superintendent of public instruction in a format provided. For purposes of applying to a joint common school district the provisions of section 15-101, "assessed valuation" means the net valuation of the part of the school district in the county, and the part of the school district in each county shall be regarded as a school district employing five or more contract classroom teachers.
A.R.S. § 15-975