Year	% of total energy use
1960	0.535343909094523
1961	0.6315694180302633
1962	0.7876870062072631
1963	1.1326208846618053
1964	1.4039629929676043
1965	2.3781285067253135
1966	3.106698384774268
1967	3.505016215796174
1968	3.7919875880672955
1969	3.988591611023409
1970	3.4930245273776803
1971	3.578729228624534
1972	3.780871015057638
1973	3.497927496658536
1974	4.338111458656914
1975	4.127502324175429
1976	4.790236432054362
1977	5.182854259854604
1978	4.863003974797688
1979	4.767610452973641
1980	5.030976882795869
1981	5.337175067677299
1982	6.1937700572112
1983	7.043576659602041
1984	7.577468252016761
1985	8.10444886652753
1986	7.7506012066656345
1987	7.17569084449885
1988	8.178464982788707
1989	9.23508297328756
1990	8.576423313716019
1991	8.871404325089761
1992	9.707945741278888
1993	11.099329935886178
1994	10.930776660697198
1995	10.99542546278712
1996	11.161294774509557
1997	11.935729450777925
1998	12.02756326756463
1999	11.516616103106998
2000	10.301790789365334
2001	10.826296437622622
2002	10.848896950492628
2003	10.72916140218999
2004	9.866971445889817
2005	10.06672703732781
2006	9.541838898460227
2007	8.436642103828973
2008	7.327008907618965
2009	10.069874538925994
2010	8.832406679293467
2011	10.808073250441803
2012	10.908522780493927
2013	11.434002090408125
2014	11.581286223808148
2015	13.12041979775749