Year	kg per kg of oil equivalent energy use
1971	4.058559044986623
1972	0.5975521150383334
1973	0.716898181378586
1974	0.7102921996675884
1975	0.7239103421815499
1976	0.7784786818766707
1977	0.7935031853742555
1978	0.7942674073875596
1979	0.8441323826988864
1980	0.9090720940553566
1981	0.9250604686834675
1982	0.9493775141082633
1983	0.8879705234672123
1984	0.9695425257786736
1985	1.0285053415043521
1986	1.075870104295102
1987	1.1309807385921558
1988	1.1751486037175782
1989	1.1118850726242135
1990	0.9043937994384279
1991	0.8625665472480583
1992	0.8919064470121926
1993	0.8983486037111302
1994	0.9264913294370518
1995	1.0408709454617586
1996	1.0516223400347686
1997	1.1353531926975664
1998	1.1051699851907224
1999	1.1394271248247798
2000	1.185525548951719
2001	1.2905208788557314
2002	1.3410813907331813
2003	1.3283839932651906
2004	1.3907993588565288
2005	1.43503551241275
2006	1.4699845131603742
2007	1.4889305907903354
2008	1.5526354624030705
2009	1.5883351248688737
2010	1.6576613400504123
2011	1.7191811428384591
2012	1.7457858268502582
2013	1.7858398874561228
2014	1.8010798235754797