Year % 1999 100 2000 99.88632 2001 99.78637 2002 100 2003 100 2004 99.69607 2005 99.47135 2006 99.54291 2007 99.23348 2008 99.37605 2009 99.81243 2010 99.77818 2011 99.82513 2012 99.67959 2013 100 2014 99.75759 2015 100 2016 100