Year % net 2005 67.05516 2006 71.53961 2007 74.20973 2008 74.76274 2009 77.28964 2010 78.27416 2011 80.18614 2012 78.77746 2013 79.381 2014 78.5674 2015 78.53982 2016 79.04928 2017 79.31285 2018 80.16872