Year	% net
1996	83.34524
1997	83.29488
1998	82.9011
1999	83.42484
2000	84.54811
2001	85.82854
2002	86.1392
2003	86.58153
2004	85.97708
2005	85.62488
2006	86.13903
2007	86.34758
2008	86.71833
2009	86.63879
2010	87.80594
2011	88.17146
2012	88.29068
2013	89.41179
2014	89.98592
2015	90.31518
2016	90.05004
2017	90.16755
2018	89.86586