Year	% net
1998	61.97727
1999	63.19142
2000	63.76998
2001	64.41759
2002	64.31124
2003	65.56578
2004	66.95903
2005	67.772
2006	68.8405
2007	70.8343
2008	70.83102
2009	72.67283
2010	74.56665
2011	76.05022
2012	75.38456
2013	76.80045
2014	79.21913
2015	78.92814
2016	79.01017
2017	78.7363
2018	78.90534