Year	% net
1973	99.4926
1976	98.38009
1979	99.50328
1985	99.00927
1995	97.06267
1996	98.22957
1997	99.13519
1999	98.83035
2000	98.4748
2001	98.66252
2002	98.59154
2003	98.44817
2004	98.64055
2005	98.408
2006	98.39118
2007	98.43845
2008	98.24087
2009	97.61927
2010	97.63938
2011	97.18455
2012	97.42164
2013	97.81952
2014	97.13266
2015	96.56912
2016	96.00704
2017	95.65574