Year % net 1995 91.41798 1996 98.29222 1997 99.86955 2004 93.55358 2005 92.75616 2006 91.67211 2007 94.73061 2008 98.30193 2009 96.56654 2011 97.24953 2012 98.51891 2013 99.28296 2014 99.10612 2015 99.58342 2016 97.8812 2017 97.91476 2018 96.43624