Year	kg per kg of oil equivalent energy use
1971	1.7999352627664864
1972	1.7151750426089964
1973	1.8371623645928896
1974	1.7732686081172604
1975	1.78149705652492
1976	1.835879840689102
1977	1.8434659908658144
1978	1.848865392025872
1979	1.7763569042385505
1980	1.650701938123265
1981	1.5383692398499094
1982	1.5132881354114678
1983	1.4079600407759516
1984	1.3701157372308206
1985	1.1803707344942136
1986	1.2292656818452132
1987	1.3159369593003738
1988	1.4362446317973616
1989	1.4169976694320914
1990	1.422547099841315
1991	1.4078550498114186
1992	1.4590368968510627
1993	1.584672126962889
1994	1.6046649573297778
1995	1.838092540583254
1996	1.9409861411748905
1997	2.0585568000173144
1998	1.9903813552613696
1999	1.8743087952593627
2000	1.8302054008588688
2001	1.8717110397810544
2002	1.8791904187979638
2003	1.9214287021205254
2004	1.967548900434833
2005	2.0101092279456143
2006	1.8359124173586623
2007	1.9292658082710337
2008	1.9132250578773644
2009	2.0300311580453103
2010	2.0687110096121666
2011	2.077128423438133
2012	2.0358471390903206
2013	2.1832914225467435
2014	2.190120866312052