Year	% of energy use
1960	32.47567433441084
1961	35.327553885835144
1962	39.03029697413562
1963	40.79585014338765
1964	42.55427637494752
1965	40.61867946709541
1966	41.47828885621616
1967	44.98525668281469
1968	50.182523611396746
1969	54.65202949479124
1970	55.955582391587775
1971	60.85222116090063
1972	63.003481803611905
1973	63.126172012072324
1974	62.331167108951455
1975	61.21090067756114
1976	66.64004324906878
1977	63.782336672257046
1978	64.22187724727176
1979	66.21002681688307
1980	67.0400028055384
1981	66.18904031920282
1982	65.05479253698925
1983	66.03919796208436
1984	67.08176253031348
1985	67.242415796798
1986	66.93517754904005
1987	66.49287643869091
1988	62.1936660191331
1989	63.96258920435268
1990	67.29646302266313
1991	68.3500202667279
1992	66.22693808248535
1993	65.77866407522053
1994	67.11193106104338
1995	67.25321851118538
1996	69.52266636440869
1997	69.20932467239213
1998	69.12483398026427
1999	66.01546910055264
2000	65.75385172678044
2001	67.55593257426062
2002	67.71055328606258
2003	70.19060852609071
2004	69.65418182900773
2005	70.64364817598816
2006	70.201671494066
2007	67.48931711530594
2008	66.73517316684662
2009	63.852967960505914
2010	64.83443952738152
2011	65.3854438379604
2012	61.954465587909354
2013	63.41705212166424
2014	62.42378603315514
2015	63.54485349359552