Year % net 1999 43.44949 2000 44.56588 2001 44.60337 2002 45.42052 2003 46.66862 2004 47.83838 2005 48.64878 2006 49.5757 2007 51.47186 2008 52.4789 2009 52.02336 2010 53.46305 2011 54.78844 2012 55.65607 2013 57.17299 2014 57.47975 2015 57.68747 2016 58.29042 2017 59.50636 2018 60.08144