2011 24,92920,870 4,059 2010 25,28521,389 3,896 2009 25,20721,803 3,404 2008 27,40423,346 4,058 2007 29,92626,112 3,814 2006 31,70928,198 3,511 2012 24,20019,843 4,357 Carbon dioxide emissions updated to reflect changes in reporting methods and conversion factors.