Year	% net
1980	96.48373
1983	93.73482
1987	94.44538
1995	81.0813
1996	84.63128
1997	85.10677
1998	86.62669
1999	88.13555
2000	89.99969
2001	91.19752
2002	89.56013
2003	82.57081
2004	87.44803
2005	87.92489
2006	91.67262
2007	88.994
2008	87.73315
2009	95.46461
2010	97.30346
2011	97.82805
2012	97.19697
2013	94.61869
2014	94.62431
2015	96.00155
2016	97.82071
2017	97.86929
2018	97.69756