Year	% net
1998	69.09174
1999	70.32852
2000	70.79927
2001	71.31685
2002	70.69343
2003	70.43652
2004	70.87587
2005	71.36337
2006	72.00892
2007	72.75401
2008	73.47872
2009	75.41877
2010	77.19324
2011	78.12165
2012	77.03932
2013	79.5286
2014	81.504
2015	81.42275
2016	81.24295
2017	80.76355
2018	80.69813