Year	kg per kg of oil equivalent energy use
1971	2.2416979321586035
1972	2.2647684492657056
1973	2.2703250851055423
1974	2.25717682500227
1975	2.3699558951311697
1976	2.39267236549856
1977	2.4061268255402943
1978	2.477823812048087
1979	2.492029549125227
1980	2.4534219410093465
1981	2.445683433865521
1982	2.5818409676931915
1983	2.619436942926074
1984	2.688550737413102
1985	2.8445869955817296
1986	2.8894618558142118
1987	2.935404742483337
1988	2.9859521318360813
1989	2.9733876869068414
1990	2.4961593508730577
1991	2.7149929619557476
1992	2.7579928098457502
1993	2.8462930486830547
1994	2.841380181152518
1995	2.953697108892312
1996	2.8551479468528718
1997	2.9176304519281953
1998	2.99357161218154
1999	2.8614564231307327
2000	2.9460704704560094
2001	2.98545980045174
2002	3.020203061094558
2003	3.0626913920146883
2004	3.1162353845397885
2005	3.202627206603098
2006	3.237935734830738
2007	3.2527842752301277
2008	3.2468151820922864
2009	3.258679168854755
2010	3.2394192674737363
2011	3.308332359086965
2012	3.274925199400085
2013	3.306811613842477
2014	3.242644147165787