Year	kg per kg of oil equivalent energy use
1971	2.981458603884229
1972	2.7677991245400198
1973	3.185570293114109
1974	3.2659393868530167
1975	3.55990811319035
1976	4.6327520213508135
1977	4.460784143404868
1978	4.0902887491285425
1979	4.081650416195816
1980	4.157995356333751
1981	3.8637189326000247
1982	3.864821228213646
1983	3.6470590215272596
1984	3.3384967752714143
1985	3.7857585350099967
1986	3.1012429716238166
1987	3.3654035869102374
1988	2.783668662990112
1989	2.99600451147912
1990	2.5331098853890404
1991	2.332574598651383
1992	2.1172847088918045
1993	2.2569555265773613
1994	2.2996969343320464
1995	2.3354454643007805
1996	2.0982150614084807
1997	2.2453721579717554
1998	2.0772458127407374
1999	1.8753084975507417
2000	1.8133169859423126
2001	1.745162838607108
2002	1.712355636822811
2003	1.5427972175532807
2004	1.7174651889387058
2005	1.714933374090498
2006	1.7123403177792298
2007	1.6389822839250547
2008	1.4199764597695153
2009	1.3182129426540752
2010	1.35733566604086
2011	1.4054888589894579
2012	1.3892353082115256
2013	1.406997629338473
2014	1.3855452085713746