Year	kg per kg of oil equivalent energy use
1971	2.0800850278386696
1972	2.085415455123528
1973	2.134197777766031
1974	2.14719470145503
1975	2.163336995473251
1976	2.1832784977138506
1977	2.1623195879705404
1978	2.2256420162514226
1979	2.2421331928004493
1980	2.2084630609175675
1981	2.18753052681209
1982	2.2075093159730677
1983	2.131384462319747
1984	2.048887055348155
1985	2.035474010471621
1986	2.074530744168475
1987	2.096021890282787
1988	2.095210568713811
1989	2.198779567183862
1990	1.8364067053768236
1991	1.8591609072769721
1992	1.8704227122534152
1993	1.9029942953249241
1994	1.9277958542615508
1995	1.9292146798820462
1996	1.9909496094714048
1997	2.0260871876344155
1998	2.0639461462229383
1999	2.0154063890757548
2000	2.072897594170608
2001	2.0534107115692284
2002	2.032724033326935
2003	2.0040781732122404
2004	2.0131452109150074
2005	1.99601549425485
2006	1.9884899432154133
2007	2.0215017478323243
2008	2.0326423819177384
2009	1.983779392325727
2010	2.0132470413483663
2011	2.0388009668975817
2012	2.023991556854332
2013	2.0269535682005855
2014	2.0076574975588306
2015	2.522794418326825