Year	kg per kg of oil equivalent energy use
1971	5.450566745976288
1972	5.743945663967129
1973	5.7835956800155905
1974	5.4777791576870065
1975	4.930003072268249
1976	5.221439691068371
1977	4.979915240166427
1978	4.779071694891905
1979	4.243068446370576
1980	3.9310972814619785
1981	3.3421256336102267
1982	2.987072718305042
1983	3.1245197946917562
1984	3.1757813227356415
1985	3.1682020471998267
1986	3.238818348171272
1987	3.0595455028662535
1988	3.041863776283194
1989	2.919473875826796
1990	2.8014304953422275
1991	2.8727082974602154
1992	2.735692337548791
1993	2.687444645105419
1994	2.6927970689951737
1995	2.7023811705383873
1996	2.734251904610354
1997	2.665349914407699
1998	2.6419872003794156
1999	2.643604872051391
2000	2.7028722658294733
2001	2.6363996363281124
2002	2.642015883969571
2003	2.6750658433977406
2004	2.6516552931604687
2005	2.6724147571003334
2006	2.6628873083303177
2007	2.667732403372569
2008	2.630108377469511
2009	2.65072913365304
2010	2.6390470448245873
2011	2.6702197648587283
2012	2.6305984951413657
2013	2.6760202991904736
2014	2.6445776535078953
2015	2.84120283658062