Year	% net
1986	72.63789
1987	73.1105
1988	72.7674
1989	72.4502
1990	72.41371
1991	73.33715
1992	74.47507
1993	76.79927
1994	78.75878
1995	79.37032
1996	79.87955
1997	79.94959
1998	79.72246
1999	79.49111
2000	80.23531
2001	81.53088
2002	82.14281
2003	83.3007
2004	83.91711
2005	84.68425
2006	84.9436
2007	84.90527
2008	85.06442
2009	84.70186
2010	85.18243
2011	85.66993
2012	85.38992
2013	86.68701
2014	87.18191
2015	87.86963
2016	88.66081
2017	88.94578
2018	88.94454