Year	thousand metric tons of CO2 equivalent
1990	21.7
1991	19
1992	17.8
1993	16.9
1994	15.2
1995	15.7
1996	15.1
1997	15.3
1998	15.2
1999	12.7
2000	14.8
2001	15.4
2002	14.6
2003	15
2004	15.6
2005	15.4
2006	15.5
2007	15.3
2008	15.8
2009	15.1
2010	15.8
2011	15.6
2012	15.3
2013	15.3
2014	15.3
2015	16.6
2016	16.3
2017	16.3
2018	16
2019	16.1
2020	13.8