Ariz. Rev. Stat. § 30-1007
I. The servicer, as agent for the qualified special purpose entity, at a minimum semiannually and quarterly during the two-year period preceding the final maturity date of the transition bonds or the final maturity date of the series, class or tranche of such bonds with the latest final maturity date, if more than one series, class or tranche has been issued, shall perform calculations for both of the following: