In November 2005, Coloradans approved Referendum C, a ballot measure that loosened many of TABOR's restrictions. This measure allows the state to retain and spend money from existing revenue sources above the TABOR limit each year beginning in FY 2005-06. The state may spend all revenue subject to TABOR for five years through FY 2009-10. Beginning in FY 2010-11, the state may spend revenue above the TABOR limit up to a capped amount known as the "Referendum C cap. The Referendum C cap grows from the prior year's cap instead of the prior year's spending by inflation plus population growth. In effect, Referendum C eliminated the ratchet-down effect.