Year	thousand metric tons of CO2 equivalent
1990	29.3
1991	30.6
1992	32.7
1993	33.5
1994	35
1995	35.9
1996	37.3
1997	38.5
1998	40.6
1999	41.9
2000	43.3
2001	44.2
2002	44.5
2003	48.2
2004	50.3
2005	51.4
2006	52.1
2007	55.8
2008	60.4
2009	61
2010	60.9
2011	59.4
2012	55.4
2013	49.9
2014	48.5
2015	50.7
2016	53.3
2017	55.1
2018	55.6
2019	56.6
2020	54.3