Year	% net
1986	79.36094
1987	79.7751
1988	79.3721
1989	79.20982
1990	78.91974
1991	79.61672
1992	80.76645
1993	82.91148
1994	84.64188
1995	85.51931
1996	86.01589
1997	86.05952
1998	85.72396
1999	85.44608
2000	85.89081
2001	86.79652
2002	86.26912
2003	87.76586
2004	88.65809
2005	88.77388
2006	88.83496
2007	88.65877
2008	88.86081
2009	89.15075
2010	88.99356
2011	89.04744
2012	89.17324
2013	89.25983
2014	89.9234
2015	90.65271
2016	90.91031
2017	91.23268
2018	91.30044