Year % net 2000 88.51682 2001 91.24836 2002 90.93192 2003 92.23459 2004 92.07622 2005 90.62146 2006 87.74714 2007 87.03107 2008 86.94637 2009 86.81535 2010 87.4003 2011 87.08558 2012 87.60779 2013 87.6292 2014 86.77036 2015 86.17302 2016 86.22262 2017 85.95203 2018 86.19406