Year	kg per kg of oil equivalent energy use
1971	13.786004018685935
1972	6.931398227189168
1973	5.61459569810031
1974	3.225592419678386
1975	3.1599181832222127
1976	5.389595774947426
1977	4.864799059470036
1978	4.533499538950172
1979	4.957565562635939
1980	3.816878957623854
1981	3.7846825780791575
1982	3.7183148727818054
1983	3.6002870371499327
1984	3.1571014262576327
1985	3.1008045903842936
1986	3.3771879672140313
1987	2.9582487642559303
1988	3.4397430453880635
1989	3.248594271767887
1990	3.2316910241908503
1991	2.941056012111643
1992	2.688007971407402
1993	2.635971333213444
1994	2.7183046136237703
1995	2.680486125356233
1996	2.6519778504656037
1997	2.5784215253038565
1998	2.6103220901941517
1999	2.5233203262336277
2000	2.5190088183631003
2001	2.5405896449171834
2002	2.57086249311513
2003	2.5376709166923557
2004	2.5359441795704916
2005	2.7643033851379055
2006	2.7474736681889906
2007	2.7704919445657423
2008	2.8918394728503074
2009	2.7882783699810663
2010	2.7535557941468056
2011	2.7800195719222844
2012	3.0322018678827325
2013	2.8323464158997083
2014	3.3410331929688994