Year	kg per kg of oil equivalent energy use
1990	2.5398801293900384
1991	2.4664548927745185
1992	2.4977898856143894
1993	2.4152953130657195
1994	2.300163750110399
1995	2.248887224259535
1996	2.196716530925346
1997	2.1898138667110456
1998	2.276068610510246
1999	2.240068844600593
2000	2.392260548607917
2001	2.398080878823766
2002	2.3522501658102812
2003	2.295568435307298
2004	2.3903072774157987
2005	2.43835704475034
2006	2.534857038886158
2007	2.477547474603516
2008	2.4949018228009843
2009	2.587011154483588
2010	2.836392742546699
2011	2.6408595719121015
2012	2.298763488736823
2013	2.635247748928186