"Costs mandated by the voters" means any increased costs expressly mandated upon a local agency or school district after September 2, 1975, by any statute or any amendment to the State Constitution adopted or enacted pursuant to the approval of a statewide ballot measure by the voters. "Costs mandated by the voters" does not include costs which are specifically reimbursed or funded by the terms of such ballot measure.
Ca. Rev. and Tax. Code § 2206.5