Year	% net
1998	67.75657
1999	68.91435
2000	69.54157
2001	70.21029
2002	69.99967
2003	70.14056
2004	70.99974
2005	71.97445
2006	72.82572
2007	73.76982
2008	74.68254
2009	76.6922
2010	78.43899
2011	79.40965
2012	78.60217
2013	80.77983
2014	82.91939
2015	82.72245
2016	82.62597
2017	82.12463
2018	82.24137