Year	thousand metric tons of CO2 equivalent
1990	40.3
1991	39.7
1992	38.4
1993	37.2
1994	39.8
1995	39.1
1996	35.1
1997	36.7
1998	36.9
1999	38
2000	36.8
2001	35.5
2002	35.8
2003	35
2004	34.6
2005	35
2006	36.1
2007	36.3
2008	35.5
2009	42.3
2010	38.6
2011	46.5
2012	41.8
2013	47
2014	45.4
2015	47.3
2016	45.8
2017	44.6
2018	44.7
2019	47.1
2020	45.8