Ariz. Const. art. IX, § 17
(2) For purposes of this section, "state revenues":
(b) Do not include:
(4) In order to permit the transference of governmental functions or funding responsibilities between the federal and state governments and between the state government and its political subdivisions without abridging the purpose of this section to limit state appropriations to a percentage of total personal income, the legislature shall provide for adjustments of the appropriation percentage limitation consistent with the following principles:
(d) If a political subdivision assumes all or any part of the cost of providing a governmental function previously funded in whole or in part by the state, the appropriation percentage limitation shall be commensurately decreased.
Any adjustments made pursuant to this subsection shall be made for the first fiscal year of the assumption of the cost. Such adjustment shall remain in effect for each subsequent fiscal year.