Year thousand metric tons of CO2 equivalent 1990 48.2 1991 47.9 1992 57 1993 78.1 1994 60.7 1995 59.5 1996 75.5 1997 77.7 1998 63.5 1999 62 2000 59.5 2001 56.9 2002 53.7 2003 57.9 2004 56.4 2005 59.5 2006 59 2007 61.5 2008 62.1 2009 61.1 2010 60.7 2011 66.3 2012 64 2013 62 2014 61.4 2015 61.3 2016 61.3 2017 65.7 2018 62 2019 68.4 2020 58.6