The investment seeks as high a level of current interest income exempt from regular federal, Arizona State and, in some cases, Arizona local income taxes as is consistent with preservation of capital. Under normal market conditions, the fund invests at least 80% of its net assets in investment grade municipal bonds rated BBB/Baa or higher at the time of purchase by at least one independent rating agency, or, if unrated, judged by the fund's sub-adviser to be of comparable quality. The fund may invest up to 20% of its net assets in below investment grade municipal bonds, commonly referred to as "high yield" or "junk" bonds.