Year % of total energy 1960 0 1961 0 1962 0 1963 0 1964 0 1965 0 1966 0 1967 0 1968 0 1969 0 1970 0 1971 0 1972 0 1973 0 1974 0 1975 0 1976 0 1977 0 1978 0 1979 0 1980 0 1981 0 1982 0 1983 0 1984 0 1985 0 1986 0 1987 0 1988 0 1989 0.3124011439813249 1990 0.14710289921565745 1991 0.14229792818969125 1992 0.24170693901321175 1993 0.24366746390311356 1994 0.3450646559602036 1995 0.36468594145642846 1996 0.35264157131723806 1997 0.36344506482028516 1998 0.30986975696743285 1999 0.23991762740282135 2000 0.24163941022796878 2001 0.20287208360447503 2002 0.22052301832114124 2003 0.23488583897353757 2004 0.2515339868536188 2005 0.3209760147759246 2006 0.3971130132430073 2007 0.505780748818804 2008 1.0429664270290728 2009 1.2653366974902345 2010 1.4920586686395165 2011 1.5311363235500748 2012 1.5669853600377748 2013 2.04173084095317 2014 2.4748050832180586 2015 2.7940900844343015