Year	% net
1986	77.79298
1987	78.24948
1988	77.8903
1989	77.7313
1990	77.61131
1991	78.40189
1992	79.59223
1993	81.97303
1994	84.01073
1995	84.58248
1996	85.26527
1997	85.20288
1998	84.62581
1999	84.17104
2000	84.52758
2001	85.22229
2002	85.43398
2003	86.45594
2004	86.86001
2005	87.30801
2006	87.33193
2007	87.22043
2008	87.65548
2009	87.77857
2010	87.92164
2011	88.07672
2012	88.0218
2013	88.34929
2014	88.58304
2015	89.12834
2016	90.20186
2017	90.25735
2018	90.3072