Year	thousand metric tons of CO2 equivalent
1970	6.155949
1971	5.888605
1972	6.076775
1973	6.136915
1974	6.189088
1975	6.193676
1976	6.476613
1977	6.379366
1978	6.296069
1979	6.164598
1980	6.062701
1981	5.906864
1982	5.851343
1983	5.861666
1984	5.872516
1985	5.807292
1986	5.763148
1987	5.891953
1988	5.895301
1989	6.042148
1990	6.267394
1991	6.224025
1992	6.211501
1993	6.350443
1994	6.37267
1995	6.436716
1996	6.463438
1997	6.573581
1998	6.643486
1999	6.726845
2000	6.72917
2001	6.453518
2002	6.497817
2003	6.511488
2004	6.56797
2005	6.569117
2006	6.577022
2007	6.582726
2008	6.590631
2009	6.596862
2010	6.59556
2011	6.6615156
2012	6.7274712