Year	kg per kg of oil equivalent energy use
1971	3.072647155171891
1972	3.0687928857333455
1973	3.561703914435925
1974	3.75801638740529
1975	4.145061078235368
1976	6.178310286876788
1977	5.539098512931588
1978	4.369088477970935
1979	4.60252438416298
1980	4.424813783118757
1981	4.246835092660869
1982	4.507288668960262
1983	3.8475583134585274
1984	3.66286682781203
1985	4.076979951410693
1986	3.2672531915169514
1987	3.4996713239263997
1988	2.888880372189087
1989	3.0267876546640586
1990	2.356647834639817
1991	2.184644837247321
1992	1.823683302184476
1993	1.9918199611986445
1994	2.0676394417945203
1995	2.140051403514335
1996	1.8288282738501207
1997	2.008620292287073
1998	1.7713452123177085
1999	1.5289012912921702
2000	1.4594618712028964
2001	1.4042627702364003
2002	1.339860455457209
2003	1.1457012682658771
2004	1.1377333430887258
2005	1.22051065992273
2006	1.235688920486143
2007	1.1539457179124009
2008	1.138434802932035
2009	1.0755871965594848
2010	1.127251213364834
2011	1.1745735966086783
2012	1.149237235348771
2013	1.1596859490858584
2014	1.1201950365854574