Year % of total 1960 96.77419354838709 1961 97.5 1962 97.7777777777778 1963 98.21428571428571 1964 97.79411764705883 1965 99.2248062015504 1966 98.23008849557522 1967 99.29577464788731 1968 98.85057471264369 1969 99.43820224719101 1970 99.44751381215468 1971 100 1972 100 1973 99.54545454545453 1974 100 1975 100 1976 100 1977 100 1978 100 1979 100 1980 99.64157706093191 1981 99.67948717948717 1982 95.25139664804469 1983 86.02941176470587 1984 81.72043010752688 1985 58.71559633027523 1986 77.77777777777779 1987 77.86561264822134 1988 72.49544626593807 1989 68.41216216216216 1990 67.6498275862069 1991 72.51036199095023 1992 76.21276497695852 1993 73.20950177935943 1994 79.3299203187251 1995 88.4394117647059 1996 93.88784482758619 1997 99.02384615384616 1998 90.51455696202532 1999 97.38091286307055 2000 99.33610328638497 2001 99.84843373493976 2002 99.10383620689655 2003 98.91065134099618 2004 99.009 2005 103.01190839694657 2006 97.14090566037736 2007 100.53804428044282 2008 94.10169117647058 2009 98.7606374501992 2010 99.20798449612403 2011 99.165953307393 2012 98.91428044280444 2013 99.02447257383967 2014 99.86723404255319 2015 98.23115151515151 2016 99.41644444444445