Year % of total 2000 97.59891782211702 2001 97.96791443850267 2002 97.9542395693136 2003 97.85123966942149 2004 96.59480646741794 2005 96.88200986989682 2006 97.0681100586378 2007 97.41468459152016 2008 97.88841534289035 2009 97.28697749196141 2010 96.53637770897832 2011 97.82796069643165 2012 98.14908295473667 2013 97.57854406130268 2014 96.94628403237675 2015 97.46690635724792