Year % 1976 84.29119 1977 86.52038 1978 62.00814 1993 89.51542 1997 94.94058 1998 93.53124 1999 93.34989 2000 93.50852 2003 94.38107 2004 98.5018 2005 96.56757 2006 97.85004 2007 98.25157 2008 98.17039 2009 98.61367 2010 99.60323 2011 98.88238 2012 96.28662 2013 99.0069 2016 99.58045