Year % net 1998 21.23195 1999 21.57845 2000 22.41829 2001 23.35455 2002 24.52033 2003 25.51508 2004 26.82411 2005 27.83074 2006 28.78221 2007 29.8421 2008 31.40325 2009 32.6019 2010 33.92753 2011 34.14694 2012 34.42672 2013 35.2822 2014 35.90736 2015 36.66352 2016 36.82146 2017 36.90465 2018 37.16256