Year % 1973 55.21542 1975 60.56266 1976 69.94697 1977 63.9576 1978 79.04055 1979 69.95192 1980 70.54161 1981 65.61503 1982 68.85246 1983 67.31583 1984 69.62604 1985 60.66532 1986 52.9327 1998 85.64676 1999 70.87846 2000 73.68687 2001 72.89152 2002 91.11979 2003 89.58806 2004 85.78546 2005 94.0667 2006 97.37673 2007 85.46966 2010 85.84154 2011 92.85269 2012 92.71281 2013 93.89279