Year % of total fuel combustion 1960 26.912568306010925 1961 26.474127557160042 1962 27.171492204899778 1963 27.62201453790239 1964 27.568042142230027 1965 29.96078431372549 1966 30.006978367062104 1967 35.66477630749843 1968 36.09813084112149 1969 34.35710567412805 1970 31.699346405228763 1971 34.79648842777335 1972 36.31651693158259 1973 38.67141162514828 1974 41.47551146931185 1975 43.548387096774185 1976 43.523049188771566 1977 43.980099502487555 1978 42.56915142991093 1979 42.94943194475385 1980 43.77074574020801 1981 46.56368927691963 1982 45.77893820713664 1983 47.1617497456765 1984 46.607669616519175 1985 49.0001834525775 1986 49.981610886355284 1987 51.01086048454469 1988 51.84025058731402 1989 52.80523255813955 1990 53.13304721030041 1991 51.87455452601568 1992 53.772802653399665 1993 53.902574038195404 1994 54.78543387031271 1995 55.14177446752908 1996 51.0925029438702 1997 50.46511627906977 1998 50.12996658002228 1999 51.6280217069561 2000 54.31916344623777 2001 53.54051054384018 2002 53.276510958600845 2003 52.39616613418531 2004 53.42099636519136 2005 53.229702762314886 2006 51.949017525225706 2007 53.28705594120049 2008 54.32203389830508 2009 53.608247422680414 2010 54.30352433469191 2011 55.10526956310089 2012 59.57943925233644 2013 60.328059224851216 2014 58.1056466302368