Year	% net
1998	60.99431
1999	62.34993
2000	63.01623
2001	63.72722
2002	63.59607
2003	64.86047
2004	66.26525
2005	67.06287
2006	68.14741
2007	70.20499
2008	70.16523
2009	72.04053
2010	74.03742
2011	75.58281
2012	74.77548
2013	76.30379
2014	78.85949
2015	78.55537
2016	78.6135
2017	78.30426
2018	78.46543