INSTITUTE INDEX: Follow the fracking money

Amount natural gas interests have spent in the past decade to fight federal regulation of hydraulic "fracking," a method of tapping underground gas reserves by injecting a mix of chemicals and other materials into a well at high pressure: $747,000,000

Amount spent on lobbying members of Congress: $726,000,000

Amount contributed to campaigns of current members of Congress: $20,000,000

Average amount donated to current members of the House Energy and Commerce Committee: $70,342

Rank of Rep. Joe Barton (R-Texas) among the biggest recipients of the industry's campaign contributions: 1

Amount the industry donated to Barton, former chair of Energy and Commerce: $514,945

Rank of U.S. Sen. Richard Burr (R-N.C.) among members of Congress from states where fracking is not currently allowed who got the most from the gas industry: 1

Amount the gas industry contributed to Burr over the past decade: $216,233

Amount it contributed to all 15 members of the North Carolina congressional delegation: $350,000

Percent of North Carolinians who say they've paid at least some attention to the fracking issue, according to a recent poll: 20

Percent who say they've paid not very much attention or none at all: 53

Size of the natural gas deposit estimated to lie beneath central North Carolina, in square miles: 1,400

Year in which Halliburton conducted the first two commercial fracking operations, in Oklahoma and Texas: 1949

Year in which Congress passed an energy bill with a provision that came to be known as the "Halliburton loophole," inserted at the request of then-Vice President Dick Cheney, exempting fracking from Safe Drinking Water Act regulation: 2005

Years in which Cheney served as Halliburton's CEO: 1995-2000

Average amount in political contributions from the gas industry to members of Congress who voted in favor of the Halliburton loophole: $73,433

Average amount received from the industry by members who voted against it: $10,894

Amount the gas industry contributed in 2010 to American Crossroads, a tax-exempt political advocacy group that works to elect Republicans and is advised by Karl Rove, former political affairs director for the Bush-Cheney White House: $3,000,000

Amount American Crossroads spent in turn to try to defeat Rep. Maurice Hinchey (R-N.Y.), who sponsored a bill to close the Halliburton loophole: $533,000

Minimum number of complaints of fracking-related water contamination that have been reported nationwide: 1,000

Month in which the shareholders of ExxonMobil, the fracking industry's biggest political donor, rejected a call for greater disclosure of environmental risks associated with gas drilling: 5/2011

Month in which Texas, long dependent on oil and gas revenues, became the first state to pass a law requiring disclosure of fracking chemicals: 6/2011

Year in which the Environmental Protection Agency is scheduled to publish preliminary findings about the potential dangers of fracking: 2012

(Click on figure to go to source. Most of the figures in this index and the graph come from "Deep Drilling, Deep Pockets," a report on the gas industry's political giving that was released this week by Common Cause.)