Year	kg per kg of oil equivalent energy use
1990	2.56992459585228
1991	2.506435091722506
1992	2.547810690038878
1993	2.49566454304309
1994	2.3920951409090314
1995	2.383646866064137
1996	2.3327499337984707
1997	2.3356171952701956
1998	2.3584060570247773
1999	2.303341459608109
2000	2.1456411865717016
2001	2.0749567085399527
2002	2.032836176412385
2003	2.056969359847958
2004	2.039989015443763
2005	2.0457944610699177
2006	2.0321136181117763
2007	2.0855993400047486
2008	2.022378146394632
2009	2.0222455375393373
2010	1.988400083372578
2011	1.967131667851576
2012	1.943063030875794
2013	1.9434848299621874
2014	1.9093172739162994
2015	1.8875131765299922