Year % net 1989 94.73198 2000 91.79287 2001 90.85464 2002 88.97418 2003 88.28813 2004 88.85032 2005 88.85073 2006 88.85265 2007 88.66398 2008 88.07856 2009 87.99978 2010 87.91347 2011 87.84316 2012 88.96676 2013 88.93992 2014 89.46177 2015 89.40543 2016 89.691