Year	% of total energy use
1971	0.817696472970853
1972	0.6800861153990321
1973	0.6802621782987607
1974	0.7131567610141851
1975	0.7329760285267644
1976	0.7553082444989861
1977	0.5325052035951245
1978	0.6288177203716996
1979	0.5760175050867339
1980	0.5306462445386866
1981	0.6714757284080213
1982	0.9444074869429346
1983	1.6157636030603229
1984	1.1527125198858854
1985	1.263773282616884
1986	3.29072328777266
1987	3.080602116260177
1988	3.1994304973495606
1989	3.479386404229711
1990	3.030739247125959
1991	2.978135647404057
1992	2.126211331871937
1993	2.4691770107363573
1994	2.492144360996826
1995	2.5640829992878333
1996	2.6770520878744697
1997	2.5991490542639557
1998	2.3462009085486106
1999	2.2872192746661577
2000	1.9606239582043221
2001	1.897565499565126
2002	1.6312482974487743
2003	2.629859160426541
2004	2.377483831425329
2005	2.5715736251467813
2006	3.1563332549423255
2007	2.7295280772889106
2008	3.4437993254145427
2009	2.5226178316221803
2010	2.9503619635729277
2011	2.9059795333588196
2012	3.0049812988825386
2013	2.9026985062760917
2014	2.565055519876254