Year thousand metric tons of CO2 equivalent 1990 181.6 1991 178 1992 170.8 1993 167.7 1994 171.7 1995 169.1 1996 165.2 1997 163.9 1998 160.7 1999 158.4 2000 147.9 2001 147.8 2002 144.3 2003 140.9 2004 137.9 2005 135.5 2006 134.7 2007 132.9 2008 131.1 2009 133.3 2010 110.4 2011 106.3 2012 105.8 2013 115.8 2014 115.3 2015 123.6 2016 126.6 2017 102.2 2018 103.1 2019 104.6 2020 104.8