Year	thousand metric tons of CO2 equivalent
1990	8.084253
1991	8.304914
1992	7.869975
1993	8.209836
1994	8.758297
1995	9.247158
1996	8.665775
1997	9.425393
1998	8.93341
1999	8.948027
2000	7.800444
2001	5.919868
2002	5.976292
2003	6.390316
2004	5.64214
2005	5.698564
2006	5.629312
2007	5.947459
2008	5.312007
2009	4.736155
2010	4.398702
2011	4.855871
2012	4.091239
2013	3.833208
2014	4.111577
2015	4.270745
2016	4.278067
2017	4.04699
2018	4.113912
2019	4.061634
2020	4.039156