Year	% net
1998	66.47982
1999	66.95838
2000	67.82463
2001	68.8394
2002	69.88445
2003	68.35831
2004	69.58987
2005	70.72011
2006	71.47666
2007	71.91685
2008	74.27278
2009	75.00194
2010	75.25359
2011	75.47695
2012	74.99047
2013	77.9791
2014	78.46832
2015	78.4996
2016	79.19809
2017	78.93313
2018	79.07735