Year	% of total energy use
1960	5.333054695132491
1961	5.61955722451136
1962	5.2531177719490385
1963	5.312182900240939
1964	4.971878126608977
1965	5.089898987580961
1966	4.911232480831043
1967	3.8360281533282
1968	3.7356446548100664
1969	3.404491676049479
1970	3.347965857024668
1971	1.9409713547571672
1972	1.9416799492913626
1973	1.7325606544345094
1974	2.170038726496581
1975	2.296669227575391
1976	2.4050608008180117
1977	2.116298278000561
1978	2.7058745249779883
1979	3.1329571623684607
1980	3.603880655909697
1981	3.910321337486973
1982	4.276854236405416
1983	4.787660013624359
1984	5.024114573626308
1985	5.698351140779056
1986	5.85124956081349
1987	6.285419145559413
1988	5.9609463420295885
1989	6.042324906053148
1990	5.416476103007648
1991	5.681327938270929
1992	5.578503372868328
1993	5.809549342725367
1994	6.00373081450934
1995	6.18943666927882
1996	6.237733241855535
1997	6.364791268718637
1998	6.779415703069338
1999	6.594271370225277
2000	6.589885407867555
2001	6.61024517675233
2002	6.312560393453844
2003	5.687051225446835
2004	5.836793536347609
2005	5.953260408834811
2006	5.8220179314980145
2007	5.424206782419187
2008	5.679681559309966
2009	5.808522605573834
2010	5.65753844340826
2011	4.599843777150707
2012	4.420587189294256
2013	4.624306412658661
2014	5.053357610932785
2015	7.3262006136095215