Year % net 1999 92.01562 2000 92.09559 2001 92.89068 2002 93.63145 2003 93.75431 2004 92.39831 2005 93.68388 2006 93.48714 2007 93.00691 2008 92.28063 2009 91.37033 2010 90.70257 2011 90.0593 2012 90.00423 2013 91.49385 2014 91.91535 2015 93.03199 2016 93.71875 2017 94.23769