Year	kg per kg of oil equivalent energy use
1971	0.6457155405959271
1972	0.6093474422420488
1973	0.5191980565376381
1974	0.5673233266999951
1975	0.5473082742935599
1976	0.5636449819600913
1977	0.5829368513816274
1978	0.5734659696718727
1979	0.5564301051903107
1980	0.5865016205777448
1981	0.5901234699663421
1982	0.5739950668998658
1983	0.5847006999370099
1984	0.6425251445941275
1985	0.6105446673361729
1986	0.6058075703422361
1987	0.4618857743697396
1988	0.38650292295791366
1989	0.4079888393030598
1990	0.3923437350617932
1991	0.3923262135330642
1992	0.3962202618914336
1993	0.4478388331386957
1994	0.49486830328227316
1995	0.5876966635003874
1996	0.6178503995700234
1997	0.6001684445173661
1998	0.6375111050646509
1999	0.7260535064489052
2000	0.74753389735285
2001	0.6781039130898677
2002	0.6497818451877412
2003	0.7724901956994114
2004	0.7079472433133844
2005	0.7438198505915651
2006	0.675845902897691
2007	0.6711589658512148
2008	0.5314149628188208
2009	0.5329752782595472
2010	0.5905380400641547
2011	0.5989928124353142
2012	0.7530312381500571
2013	0.8180874499967372
2014	0.8824905332951404