Year	% of total energy
1971	61.484504050971445
1972	60.74178703239623
1973	61.524667550444825
1974	61.792213962275966
1975	62.18239416755268
1976	57.75014979523857
1977	61.80956396070042
1978	60.605255861652
1979	61.82132445371633
1980	60.86605762745776
1981	60.19940678828289
1982	57.918875313491306
1983	52.779135825082925
1984	55.72725737661164
1985	54.77430907537942
1986	57.04228254208381
1987	57.5189233660898
1988	60.60116545354851
1989	59.862342863874254
1990	46.38677791763888
1991	45.56358708478197
1992	47.26603724095298
1993	48.059290878740555
1994	54.94399927347341
1995	46.89334349145115
1996	51.940027248351704
1997	54.79091063205757
1998	55.26753550064447
1999	53.768303668846976
2000	39.7401221628688
2001	38.57273552113363
2002	42.219047856679474
2003	39.32640690444023
2004	40.48908985562651
2005	40.84351783522362
2006	51.09720343362041
2007	41.14739838056551
2008	41.62378302683089
2009	39.4418364158737
2010	39.186486283405905
2011	49.20982844868398
2012	44.703469561856586
2013	44.64754066823792
2014	45.74898415707392