Year % of total fuel combustion 1960 32.66838770241728 1961 33.042805932382095 1962 34.61474785603126 1963 34.565992865636154 1964 34.582071310909186 1965 35.07539712509126 1966 34.40755783153805 1967 34.71097775009908 1968 34.929157861918455 1969 35.11840811076644 1970 38.000772541662066 1971 37.72013961047611 1972 37.62079898541534 1973 39.64677697921889 1974 39.3455949598618 1975 39.604496498146084 1976 39.556199847044184 1977 41.64640577296697 1978 41.48926664730717 1979 41.01298106791355 1980 39.887156269032324 1981 40.109896602658786 1982 39.3447821632434 1983 39.65876341091278 1984 40.56996513871183 1985 39.678928220823465 1986 39.47477827050998 1987 39.340121919019126 1988 40.01580217386662 1989 40.31006948045215 1990 42.61964251393428 1991 42.64648109998562 1992 42.970024663251756 1993 41.84336819563679 1994 43.96417125482784 1995 42.64847932257861 1996 42.59289003105257 1997 42.639247774906686 1998 43.294345183275006 1999 43.89197733690923 2000 44.428866846587916 2001 44.072652671418226 2002 45.41425307812754 2003 46.79933665008292 2004 46.489529577344655 2005 46.909575687586496 2006 46.509627131476165 2007 49.834223003216074 2008 50.00892379082635 2009 48.71973885314262 2010 49.709485348347755 2011 51.71053083073123 2012 53.61719376907869 2013 53.854912166558236 2014 53.09642193113079