Year	kg per kg of oil equivalent energy use
1960	3.905528030879309
1961	3.627338928003332
1962	3.4367234138802742
1963	3.93047844065686
1964	3.5837411268326314
1965	4.1592254786953635
1966	3.956911029998957
1967	3.7015073316305815
1968	3.9161816112168863
1969	4.002386382114939
1970	3.148924098846293
1971	3.2006720052252495
1972	3.1301501631604802
1973	3.154389105883945
1974	3.2167680854040066
1975	3.310031480061875
1976	3.3693662201030343
1977	3.4358514014271226
1978	3.3425191885640952
1979	3.361907385454503
1980	3.4326848123328078
1981	3.463338565924158
1982	3.4651946282858885
1983	3.5276258255719366
1984	3.4885080709139613
1985	3.452727602663805
1986	3.544285090822254
1987	3.5420886301996717
1988	3.5597673135241092
1989	3.5127260384782555
1990	3.5269589652176645
1991	3.507531640068039
1992	3.5297459201478287
1993	3.570605208666644
1994	3.546822415455017
1995	3.6528175905302604
1996	3.536130291617521
1997	3.4425991393337747
1998	3.400885385556694
1999	3.397955395031754
2000	3.4873757073233045
2001	3.4498896828051224
2002	3.4109315554211586
2003	3.439354117986525
2004	3.3614434391609542
2005	3.3703996854337706
2006	3.331703875380379
2007	3.452272979707082
2008	3.301424929325636
2009	3.21918249482362
2010	3.1726834203526955
2011	3.1621706994721586
2012	3.017287675756819
2013	3.106185517615732
2014	3.0063490374258253
2015	2.880322901095446