Year % of total fuel combustion 1960 30.566507075936055 1961 31.311399749456054 1962 31.19784799709763 1963 30.429421697624267 1964 31.917465848217915 1965 31.47607707632922 1966 31.755037546812495 1967 31.947276323797922 1968 31.85504720511717 1969 32.25129193515178 1970 33.44972850972815 1971 34.2754977736705 1972 34.446175058727405 1973 34.85160878150773 1974 36.01202979276531 1975 35.65999929160195 1976 37.03524729283557 1977 36.80799037121259 1978 37.32366418554427 1979 37.503643885060185 1980 38.787406184397675 1981 39.13397502787814 1982 39.684194845821544 1983 39.66102195675617 1984 39.16720566041434 1985 38.94510531853168 1986 39.18750341569819 1987 38.90936630979681 1988 38.6785706699896 1989 40.164752340714635 1990 47.271824953848935 1991 47.485665386293405 1992 48.68987519475014 1993 48.01766528895614 1994 48.52744577994819 1995 47.445231734231626 1996 47.39785853651776 1997 46.98421965198056 1998 47.20140608772069 1999 47.010163043916265 2000 47.51602985965197 2001 47.40950580320021 2002 47.97500845590444 2003 48.220929751654694 2004 47.73121996458984 2005 48.26600407347025 2006 48.932239341669806 2007 48.98032406180882 2008 47.99809153925869 2009 47.97667400405999 2010 48.15214625411131 2011 49.10570572566745 2012 49.5444932226744 2013 48.59561244158926 2014 48.06765603043492