Year	% net
1998	59.74304
1999	60.04734
2000	61.05783
2001	61.31407
2002	61.46597
2003	62.01971
2004	62.74458
2005	63.464
2006	63.91914
2007	65.23476
2008	66.08593
2009	66.39911
2010	67.96655
2011	69.38307
2012	69.28063
2013	71.03323
2014	72.07815
2015	72.17162
2016	71.98174
2017	72.56545
2018	72.46928