Year	kg per kg of oil equivalent energy use
1990	3.58068886032563
1991	3.438504119132764
1992	3.6214271529673776
1993	3.36917433527772
1994	3.2580655800495597
1995	3.116969314848662
1996	3.006818892187285
1997	2.9981738395704434
1998	3.174489753485057
1999	3.1573977309527383
2000	3.1435488205646633
2001	3.1102357880125124
2002	3.1539467738584084
2003	3.2327791124436644
2004	3.1894763867530416
2005	3.285359788155702
2006	3.1253349802478434
2007	3.4889602968621856
2008	3.3319287859883375
2009	3.0721101885425486
2010	3.357955375120788
2011	3.208702356325241
2012	3.0390589711463267
2013	3.1492739438362523
2014	2.951698974408836
2015	2.799827966328471