Year	kg per kg of oil equivalent energy use
1971	2.658281509963446
1972	2.616786030556009
1973	3.684412600058801
1974	3.4654889269930207
1975	4.133908598718513
1976	4.583746320049518
1977	4.649280693396987
1978	4.905431013510226
1979	4.950331885403711
1980	4.8274719532855555
1981	4.264196843877522
1982	4.130784525708583
1983	3.3803838770652566
1984	3.9476969471504435
1985	4.646103650192183
1986	3.6564838983381374
1987	3.1199264439561736
1988	3.1791416217722803
1989	4.545904765205173
1990	3.495837583216594
1991	3.565719906553547
1992	3.535099860819821
1993	3.406364828920762
1994	3.6302507816485914
1995	3.4372280880437405
1996	3.379706438125953
1997	3.4163151327906838
1998	3.2781413138231836
1999	3.2926533525974047
2000	3.1755119748080585
2001	2.901181819851812
2002	2.272142898372768
2003	1.959482892910912
2004	1.703796350568214
2005	1.5414394181016258
2006	1.1957654511987106
2007	1.0762334698511131
2008	0.9986686030681614
2009	0.9283503611946011
2010	0.9385953969077906
2011	1.3781839347737799
2012	1.6076292624924926
2013	1.0765488563368215
2014	1.083669533596514