Year	thousand metric tons of CO2 equivalent
1990	37.5
1991	38.3
1992	37.3
1993	34.2
1994	34.6
1995	34.3
1996	35.4
1997	38.4
1998	39.7
1999	39.9
2000	40.2
2001	40.7
2002	43.2
2003	45.4
2004	49.1
2005	52.7
2006	61.7
2007	64.9
2008	68.1
2009	69.3
2010	71.2
2011	71.8
2012	70.6
2013	66.7
2014	75.7
2015	75.2
2016	67.8
2017	68.3
2018	57.5
2019	62.9
2020	53.6