Year: 2005
Gallons (Trillions): 4.09

Year: 2006
Gallons (Trillions): 3.86

Year: 2007
Gallons (Trillions): 4.27

Year: 2008
Gallons (Trillions): 3.79

Year: 2009
Gallons (Trillions): 3.60

Year: 2010
Gallons (Trillions): 3.82

Year: 2011
Gallons (Trillions): 3.80

Year: 2012
Gallons (Trillions): 3.96

Year: 2013
Gallons (Trillions): 3.76

Year: 2014
Gallons (Trillions): 3.66