There shall be established a state school aid fund which shall be used exclusively for aid to school districts, higher education, and school employees’ retirement systems, as provided by law. Sixty percent of all taxes imposed at a rate of 4% on retailers on taxable sales at retail of tangible personal property, 100% of the proceeds of the sales and use taxes imposed at the additional rate of 2% provided for in § 8 of this Article, and other tax revenues provided by law, shall be dedicated to this fund. Payments from this fund shall be made in full on a scheduled basis, as provided by law. Beginning in the 1995-96 state fiscal year and each state fiscal year after 1995-96, the state shall guarantee that the total state and local per pupil revenue for school operating purposes for each local school district shall not be less than the 1994-95 total state and local per pupil revenue for school operating purposes for that local school district, as adjusted for consolidations, annexations, or other boundary changes. However, this guarantee does not apply in a year in which the local school district levies a millage rate for school district operating purposes less than it levied in 1994.