Year	% net
1979	86.84263
1991	93.79326
1993	95.93359
1994	95.41511
1995	93.05896
1996	93.58783
1997	93.75928
1998	98.75629
1999	94.88492
2000	95.26391
2001	94.9661
2002	95.17207
2003	95.41716
2004	95.35803
2005	96.08229
2006	96.391
2007	96.13509
2008	95.41035
2009	94.68926
2010	94.28708
2011	93.79525
2012	93.19848
2013	94.89586
2014	94.9359
2015	95.67699
2016	96.32286
2017	96.3946