Year	% of energy use
1971	51.13350837571397
1972	50.29872999374974
1973	53.19077719685791
1974	51.6701362738736
1975	53.07034933648508
1976	53.63063800397207
1977	54.50344672378045
1978	53.725736032563
1979	47.699576167786006
1980	45.68748445497323
1981	42.91759437803582
1982	39.2915482157625
1983	39.06136834787824
1984	29.437029282876537
1985	30.878789656460153
1986	31.02535217859277
1987	35.876248347528126
1988	37.227500561197175
1989	38.669996080423324
1990	40.002564346657444
1991	41.336050954027606
1992	43.82785686797995
1993	45.109551896726664
1994	48.666992356529015
1995	52.94751969190475
1996	54.50075688106046
1997	56.043524334502436
1998	54.177612037511935
1999	51.72134030339167
2000	51.11644654981276
2001	52.02944846261802
2002	48.206693529935016
2003	47.08691415826466
2004	46.162087307456
2005	44.93143365571436
2006	44.53711957709041
2007	42.71327482365563
2008	42.71937825696146
2009	38.541605399547684
2010	41.708647365496404
2011	40.923273379313606
2012	41.80191567990924
2013	45.32488659999978
2014	45.76800308299209