Year % net 1999 80.80743 2000 82.4234 2001 84.3954 2002 84.3447 2003 84.61855 2004 82.88759 2005 81.7847 2006 82.2127 2007 83.01394 2008 82.95586 2009 82.68733 2010 84.72222 2011 86.38006 2012 86.6738 2013 88.65188 2014 89.11743 2015 89.29321 2016 88.4149 2017 89.01519 2018 88.51419