Year % net 1998 49.58251 1999 49.9311 2000 50.93565 2001 51.61339 2002 52.22729 2003 53.10246 2004 54.02102 2005 54.71912 2006 55.40113 2007 56.49204 2008 57.28407 2009 57.79404 2010 59.20003 2011 60.32994 2012 60.64235 2013 61.86824 2014 62.6777 2015 62.70272 2016 62.78626 2017 63.20392 2018 63.29202