Year	% net
1986	77.56741
1987	78.01172
1988	77.65126
1989	77.47211
1990	77.29252
1991	78.26223
1992	79.45208
1993	81.70531
1994	83.54604
1995	84.21885
1996	84.53154
1997	84.6808
1998	84.34303
1999	84.11826
2000	84.58834
2001	85.54786
2002	85.44178
2003	86.92639
2004	87.82023
2005	88.37045
2006	88.18429
2007	87.99102
2008	88.21791
2009	88.58001
2010	88.55204
2011	88.70855
2012	88.92552
2013	89.16642
2014	89.86311
2015	90.6114
2016	90.8785
2017	91.19571
2018	91.268