Year	kg per kg of oil equivalent energy use
1971	2.533870875727231
1972	2.906580697794073
1973	3.0206120478984078
1974	2.37987384802943
1975	2.310452662067301
1976	2.2600336372003333
1977	2.463792646764305
1978	2.5035387009638668
1979	3.353633799504846
1980	1.6833384501736417
1981	2.7224257077855016
1982	2.7153224113556864
1983	2.6829125688612376
1984	2.6459676893077297
1985	2.9000058144498646
1986	2.765101249313564
1987	2.618590986064922
1988	2.513190305579043
1989	3.1047811587441463
1990	2.263544696028396
1991	2.1965007765244837
1992	1.6492501433890472
1993	1.5553793961070432
1994	1.5120223440161715
1995	1.4668083829227399
1996	1.3884973216802932
1997	1.222319218574627
1998	1.3484257129800956
1999	1.6580813040446576
2000	1.7678249172970235
2001	1.7617433599509777
2002	1.8621391360568234
2003	2.0861006312611567
2004	1.9810520910489693
2005	1.8781561213814926
2006	1.9146129881672191
2007	2.0899355735263603
2008	1.9906444484649841
2009	2.0150466142785644
2010	2.1562662131916412
2011	2.2678359220710385
2012	2.295537985389753
2013	2.0647228098851516
2014	2.234863615521256