Year	kg per kg of oil equivalent energy use
1971	5.112362778978741
1972	5.138238398015436
1973	5.157961320129598
1974	4.707383408153982
1975	4.4125805622299525
1976	4.626173361372884
1977	4.382940438511235
1978	4.439378352243288
1979	4.0395777820935495
1980	3.6515103137322065
1981	3.079002568406362
1982	2.9014072458020346
1983	3.232520080465475
1984	3.17738504275158
1985	3.082382212677313
1986	3.04284487580145
1987	3.1315737853020154
1988	3.239786004782108
1989	3.054470550490804
1990	2.810769266053792
1991	2.8459150598035077
1992	2.841521999319676
1993	2.7764855396482475
1994	2.783240220776235
1995	2.7779752910852364
1996	2.8516188867893555
1997	2.76767245349011
1998	2.7264893379436725
1999	2.7028096291708734
2000	2.8011194701645223
2001	2.7303829077188952
2002	2.7433606935341732
2003	2.7609158553161417
2004	2.735160985056996
2005	2.7289243047909038
2006	2.7680567674064918
2007	2.7688779041709437
2008	2.7210769959280987
2009	2.7800151992363946
2010	2.7917748637659723
2011	2.789000167486516
2012	2.803544291870522
2013	2.8155848122344267
2014	2.7978447513396945