Year % 1998 100 1999 98.41176 2000 99.12745 2004 100 2005 99.12079 2006 98.7748 2007 98.70389 2008 97.1913 2009 96.64537 2010 95.43236 2011 93.81716 2012 90.91398 2013 89.48228 2014 87.32456 2015 87.29868 2016 91.66313