Year	% of total energy use
1971	8.349077084140545
1972	9.010934994221575
1973	9.896350328519175
1974	9.926069872616928
1975	9.279933108540138
1976	9.800968509251513
1977	9.720246208647655
1978	8.251241466249057
1979	10.187305886222916
1980	11.277214030852925
1981	10.911654807377316
1982	9.818807978604672
1983	5.9682874129894845
1984	3.9426650258645486
1985	5.90234688149743
1986	8.307928429209088
1987	8.198716988133212
1988	8.615108693115713
1989	8.693076240504332
1990	7.263874559088935
1991	7.45006114961272
1992	7.728476289817861
1993	7.707873305969894
1994	7.028283545504377
1995	8.111869761858697
1996	8.736342321341803
1997	8.00916973825863
1998	4.229633131536927
1999	5.886311855788563
2000	7.98257811924926
2001	7.515350212977085
2002	5.8984326779730125
2003	4.402326137280276
2004	5.817895165363888
2005	6.372791906342705
2006	5.954569562512959
2007	4.092697176101722
2008	6.317938444855521
2009	6.050518577437796
2010	5.479964638540049
2011	5.817147353260981
2012	5.99735280678279
2013	5.823055077296942
2014	5.8686492791920495