Year	kg per kg of oil equivalent energy use
1971	2.257400758363054
1972	2.253481894713378
1973	2.2917815540179247
1974	2.2979913361160076
1975	2.2517563760426165
1976	2.2603638323809743
1977	2.239058431235538
1978	2.2840955933086557
1979	2.3184526330677637
1980	2.299004303389416
1981	2.2608100265955384
1982	2.274745443766619
1983	2.194767980815646
1984	2.116850660458615
1985	2.1293748132687504
1986	2.161196697161723
1987	2.1849331611245097
1988	2.200405056033095
1989	2.284412026111143
1990	1.9146822934172827
1991	1.9244947909580283
1992	1.917106182771856
1993	1.9679310503910177
1994	1.9611785468659988
1995	1.986542681152189
1996	2.0522185273497433
1997	2.093278580190462
1998	2.1022711894808963
1999	2.053828088033945
2000	2.102107384780416
2001	2.0812544387624654
2002	2.056077198224445
2003	2.030464730423997
2004	2.0353119290563955
2005	2.038430368871466
2006	1.9976410525685093
2007	2.044135882438699
2008	2.056666829263473
2009	2.013735628923742
2010	2.026437075412484
2011	2.0641562109184477
2012	2.0476296654821557
2013	2.0660518277668096
2014	1.9857173110785333
2015	2.4827364174964117