Year	kg per kg of oil equivalent energy use
1971	4.4329345410622105
1972	4.086117689364993
1973	3.4006357288894034
1974	2.837438660114351
1975	2.596245780757694
1976	2.6273089672553898
1977	2.2677786446083172
1978	2.5367371893371295
1979	1.6941725894827968
1980	2.3604251995077736
1981	2.448432371796957
1982	1.8465319157881444
1983	1.7744959762349795
1984	2.2513794186077147
1985	2.0788093007233845
1986	2.3256553430548883
1987	1.9042650129978749
1988	1.6315219131563203
1989	1.5228221139909646
1990	3.211040093760175
1991	13.28205284436555
1992	2.6079068198633415
1993	2.378943020818597
1994	2.3390660202943607
1995	2.2850226365970308
1996	2.2643548341638486
1997	2.3171592892874355
1998	2.3759777157234687
1999	2.4269713606279644
2000	2.5201787943169727
2001	2.544080754589771
2002	2.5989908088021427
2003	2.5401363692049626
2004	2.545736603686966
2005	2.558815662158712
2006	2.7147887092066174
2007	2.6171955535088753
2008	2.539213982498195
2009	2.389032937995713
2010	2.4394091299056284
2011	2.5063848579272605
2012	2.2475090063700573
2013	2.4405950128275795
2014	2.467034990248305