a. Except as otherwise provided, the principal of the foundation aid stabilization fund may be expended upon order of the governor, who may direct such a transfer only to offset reductions in state aid to school districts, which were made by executive action, pursuant to law, due to a revenue shortage.

b. Whenever the principal balance of the foundation aid stabilization fund exceeds fifteen percent of the general fund appropriation for state aid to school districts, for the most recently completed biennium, as determined by the office of management and budget, the legislative assembly may appropriate or transfer any excess principal balance. Such amount may be used for education-related purposes, as provided by law.