Year % net 1998 53.89543 1999 54.10659 2000 54.93954 2001 55.54719 2002 56.06077 2003 56.94918 2004 57.81391 2005 58.49775 2006 59.11553 2007 60.08915 2008 60.84241 2009 61.3097 2010 62.54485 2011 63.53369 2012 63.79482 2013 64.8996 2014 65.64805 2015 65.71337 2016 65.82859 2017 66.19644 2018 66.27183