The Virginia transferable credit program is the largest among the States in dollar value of property conserved. By the end of 2010, $2,512,000,000 of property value had been donated as easements in Virginia for which tax credit was claimed. The qualifying easements cover over of Virginia landscape. The Virginia program now (2011) grants about $110 million of new tax credit each year. The credit allowance is 40% of the appraised value of the easement donation, so this equates to $275 million of property value donated per year for protection of wildlife habitat, farmland and woodland, and scenic open space—in perpetuity. The other state tax credit programs are smaller in dollar measurement, but are very significant in the area and the conservation values that they cause to be protected. The concept of state tax credit action (in the absence of a federal tax credit) that Philip Tabas and The Nature Conservancy promoted in the 1990s has borne remarkable fruit, and continues to expand today.