Year	kg per kg of oil equivalent energy use
1960	3.339040210018144
1961	3.32525071167327
1962	3.322401256948315
1963	3.4597970539498695
1964	3.527973316826496
1965	3.4556002938782435
1966	3.4246564975303233
1967	3.4023785183170983
1968	3.4522626495587767
1969	3.4350085411505344
1970	3.419330470144511
1971	2.2323055305261383
1972	2.2428922442409913
1973	2.2687559261716075
1974	2.2589240928418786
1975	2.2811545322355253
1976	2.3212253888875027
1977	2.326070809296219
1978	2.3553475539208457
1979	2.367714025994687
1980	2.333468356095858
1981	2.2852590630803116
1982	2.3213803286096764
1983	2.3491969919567643
1984	2.3629313436690746
1985	2.422063678137007
1986	2.4351338988276976
1987	2.457577726791956
1988	2.486427545182432
1989	2.4858744489347546
1990	2.3099341421600204
1991	2.346071956030547
1992	2.3643689007731097
1993	2.362285677022126
1994	2.3650697064891486
1995	2.397358807256487
1996	2.3797001770611033
1997	2.3861943776840606
1998	2.4044684745688216
1999	2.351256982616404
2000	2.3857938677622226
2001	2.3996860683521053
2002	2.4133784272454903
2003	2.444541797445933
2004	2.4786812244042
2005	2.521344488121167
2006	2.5537093015214736
2007	2.589173466554724
2008	2.5897324772202723
2009	2.5937685376180926
2010	2.604732682551996
2011	2.661074942255932
2012	2.6481582605455047
2013	2.662575822102562
2014	2.6459226683753556
2015	2.6699973841531652
