Year	% of total energy use
1971	1.4338901724561341
1972	2.543644545607254
1973	2.364593207112011
1974	2.4773799983760907
1975	2.3885141627468114
1976	2.3936187036252194
1977	1.33463693219734
1978	1.6624367218294296
1979	2.6758915758028174
1980	2.880191613145777
1981	2.7007668350654317
1982	2.2671095438798896
1983	4.716914330801057
1984	13.748515114041949
1985	14.573594925016414
1986	12.877926483745899
1987	12.080181512094997
1988	10.659345067841706
1989	18.888593362384825
1990	2.507194598776285
1991	2.316476734140669
1992	1.9380304638592627
1993	2.279372514910537
1994	1.8147731733150225
1995	1.6627202051094094
1996	1.6121140138388002
1997	1.4663726061030926
1998	0.911157096984027
1999	1.1851547771929924
2000	0.7570247401886806
2001	0.8543619669336258
2002	1.070084475073278
2003	1.1543917262831407
2004	1.1234601105068127
2005	1.3648001252515343
2006	1.2457566299129934
2007	1.1878926405892916
2008	1.8580627759294306
2009	1.5074393467913922
2010	2.0347071138836372
2011	1.9250129314882884
2012	2.5107447410189723
2013	3.181471547520066
2014	3.3417491884790094