Year	kg per kg of oil equivalent energy use
1971	2.239832226111364
1972	2.245414416918337
1973	2.2828571872213703
1974	2.2858700119230067
1975	2.2540711539423524
1976	2.2583120738906493
1977	2.2372043995882165
1978	2.2789363216913507
1979	2.3127228057170353
1980	2.2929390784788435
1981	2.25936978738913
1982	2.2763156412124723
1983	2.1852082935926873
1984	2.116922919829362
1985	2.129401485015271
1986	2.162700152348058
1987	2.1831761866453614
1988	2.197944424818871
1989	2.270945594445222
1990	1.9211794912719762
1991	1.9238725640055798
1992	1.9127326061758843
1993	1.9665764569220507
1994	1.9617747076620384
1995	1.9894674260691279
1996	2.053502975350096
1997	2.096665182475635
1998	2.1073628083785194
1999	2.059680780399732
2000	2.104512563065843
2001	2.083404619685198
2002	2.0595502403580186
2003	2.0333486505453866
2004	2.040552328488766
2005	2.046307746973179
2006	2.006537651921894
2007	2.054890976370974
2008	2.0622794070299695
2009	2.0193229243032245
2010	2.033192960287318
2011	2.0699436862459524
2012	2.0528295387494238
2013	2.0702409449754944
2014	1.990359099048896
2015	2.4827364174964117