Year % 1987 86.03102 1999 97.97378 2000 90.68627 2002 97.82323 2004 99.03398 2005 92.9678 2007 97.08084 2008 91.59973 2009 98.04958 2010 99.86204 2011 99.94051 2012 94.88255 2013 96.44359 2014 96.16173