Year thousand metric tons of CO2 equivalent 1990 150.5075 1991 151.365 1992 154.99 1993 158.5525 1994 159.33 1995 161.41 1996 163.345 1997 165.3175 1998 169.8175 1999 171.585 2000 152.1325 2001 164.5625 2002 168.2925 2003 162.325 2004 164.775 2005 167.47 2006 182.6025 2007 162.2275 2008 184.2275 2009 186.72 2010 197.8775 2011 212.62 2012 219.625 2013 223.4125 2014 230.25 2015 233.4275 2016 229.3975 2017 231.1875 2018 231.4025 2019 231.53 2020 231.18