Year % of total 1960 100 1961 100 1962 100 1963 100 1964 100 1965 100 1966 100 1967 100 1968 100 1969 100 1970 100 1971 100 1972 100 1973 100 1974 100 1975 100 1976 100 1977 100 1978 100 1979 100 1980 100 1981 100 1982 100 1983 100 1984 100 1985 100 1986 100 1987 100 1988 100 1989 100 1990 94.91058823529413 1991 93.71222222222222 1992 55.684074074074076 1993 88.85423076923077 1994 91.675 1995 99.36387096774195 1996 100.84250000000002 1997 95.1128125 1998 81.4888888888889 1999 90.18837837837837 2000 96.76805555555555 2001 82.94404761904762 2002 76.235 2003 83.57348837209302 2004 84.6902380952381 2005 96.5 2006 89.4390243902439 2007 120.32343750000001 2008 123.76125 2009 36.67 2010 100.84249999999999 2011 107.11500000000001 2012 78.27634615384615 2013 127.1990625 2014 113.06583333333333 2015 108.08 2016 118.39171428571429