Year	% net
1986	72.19361
1987	72.60398
1988	72.18098
1989	71.80829
1990	71.67059
1991	72.45719
1992	73.5387
1993	75.60416
1994	77.30247
1995	78.14952
1996	78.56221
1997	78.80927
1998	78.91604
1999	78.93611
2000	79.94168
2001	81.52584
2002	81.70078
2003	83.32874
2004	84.4627
2005	85.30231
2006	85.48944
2007	85.60443
2008	85.83826
2009	85.72515
2010	85.98374
2011	86.39243
2012	86.32804
2013	87.41252
2014	88.28568
2015	89.09883
2016	89.36063
2017	89.77384
2018	89.81395