Year	% of total energy use
1971	0.48694051129975724
1972	0.7460821665403108
1973	0.5368848194776819
1974	0.8480099958528602
1975	1.1127552330373915
1976	0.9271377067757771
1977	0.5868344015530886
1978	0.4128249969243647
1979	1.7839433730112497
1980	3.253346465505663
1981	4.18019512447305
1982	4.19578998011201
1983	2.42907340642702
1984	0.9112457232980973
1985	3.158816912334094
1986	2.504875330231873
1987	2.1571306290518324
1988	2.5001540253801027
1989	3.1027719067457293
1990	2.3816767922067936
1991	2.2984372186088566
1992	1.8487411850544229
1993	1.5451984181374652
1994	1.5697113656097468
1995	2.387912531184674
1996	1.8761212355295054
1997	1.7074570101061675
1998	1.405189176712587
1999	1.2093513942558036
2000	1.2832963054874604
2001	1.4369015855728322
2002	1.1810747109211266
2003	1.3893686406604302
2004	0.8332390652946506
2005	0.6484163785998732
2006	0.7586963864987832
2007	0.8909769501809698
2008	0.9752852703558366
2009	1.241040566668551
2010	0.9450014444786868
2011	0.8235670996726193
2012	0.8172671714307947
2013	0.6498663604558808
2014	0.7947767115823704