Year % of total fuel combustion 1960 33.619141095205464 1961 33.84663216225608 1962 33.2317335675294 1963 32.84623316362699 1964 34.0219384206866 1965 33.91949551358474 1966 33.714130504250015 1967 33.6959684458957 1968 34.67667930992292 1969 35.11187365519569 1970 37.4078298773781 1971 39.028205154417854 1972 39.45408438329906 1973 39.00287959856685 1974 40.645255616745445 1975 39.88905439416507 1976 41.31190860162823 1977 41.05035715695173 1978 41.185865442204026 1979 41.37313052654561 1980 43.15365758272367 1981 43.92308146515244 1982 44.79801399232678 1983 44.59386105961757 1984 44.12405497936767 1985 42.63373748233092 1986 42.707940353036946 1987 42.45152493433058 1988 43.02815407461284 1989 44.485617579778705 1990 43.826773160900586 1991 44.62651442517214 1992 44.766852364514634 1993 44.11096839304555 1994 44.829030981587955 1995 44.3112444408129 1996 43.98805162599335 1997 43.7859649122807 1998 44.19664466771348 1999 44.07935904199846 2000 44.83505662235353 2001 45.39004533593082 2002 46.32950697424237 2003 46.84225914916426 2004 47.190536544148706 2005 47.761706238242915 2006 47.57209884266499 2007 51.181502829868805 2008 48.058095889174105 2009 47.666976718357375 2010 47.681421060260654 2011 48.46918543435753 2012 48.99970461075754 2013 48.44866860419449 2014 48.46737732796881