Year	% net
1986	78.55204
1987	78.98693
1988	78.60573
1989	78.44486
1990	78.24199
1991	78.98708
1992	80.15837
1993	82.4252
1994	84.31308
1995	85.03403
1996	85.62601
1997	85.61568
1998	85.15659
1999	84.78855
2000	85.18859
2001	85.98569
2002	85.83837
2003	87.09157
2004	87.73305
2005	88.01966
2006	88.06183
2007	87.9194
2008	88.2413
2009	88.44542
2010	88.44297
2011	88.54826
2012	88.58138
2013	88.79159
2014	89.23449
2015	89.86954
2016	90.54602
2017	90.73148
2018	90.7899