Year % of total 1960 93.53099730458221 1961 93.91534391534393 1962 94.81481481481481 1963 93.44978165938865 1964 97.63313609467454 1965 97.58308157099698 1966 98.05825242718446 1967 97.81357882623705 1968 97.52066115702479 1969 97.89658194566171 1970 98.33836858006042 1971 98.01324503311258 1972 98.50034083162917 1973 98.04054054054055 1974 97.35483870967741 1975 97.49134948096886 1976 98.2421875 1977 98.0732177263969 1978 97.22814498933901 1979 97.43326488706366 1980 97.55381604696673 1981 97.98590130916415 1982 97.60536398467433 1983 97.46716697936209 1984 97.48953974895397 1985 97.65976597659767 1986 98.27437446074202 1987 98.14004376367616 1988 98.5627836611195 1989 98.04878048780488 1990 95.66977653631284 1991 100.1549375 1992 93.90110375275938 1993 90.8128526645768 1994 87.26830472103005 1995 91.79805369127516 1996 99.59434272300469 1997 101.74335260115606 1998 97.63095541401273 1999 96.13486486486487 2000 98.3813153153153 2001 103.0252380952381 2002 106.31381962864721 2003 115.3094064516129 2004 132.89104582843714 2005 107.53131212723656 2006 95.77237138263666 2007 104.05317436661699 2008 101.92288766368023 2009 101.80943257676903 2010 94.39001260239446 2011 92.26028664495114 2012 84.76773175542407 2013 94.55802068965518 2014 91.99792563600782 2015 100.94550561797753 2016 87.87908203125