Year % net 1999 39.66008 2000 40.60467 2002 50.94075 2004 50.03848 2005 53.29682 2007 62.2369 2008 60.8427 2009 64.31607 2010 63.72856 2011 63.17685 2012 63.82419 2013 65.55798 2014 66.95176 2015 67.83227 2016 68.88978 2017 70.27235 2018 70.60614