Year	% net
1977	76.15987
1993	95.6409
1994	97.48127
1995	98.58061
1996	96.91298
1999	92.47698
2000	92.18191
2001	93.00415
2002	93.7274
2003	95.84829
2004	97.29944
2005	96.89721
2006	97.62784
2007	95.89939
2008	94.14133
2009	92.99165
2010	92.22014
2011	92.13048
2012	92.81516
2013	93.20421
2014	93.45839
2015	93.23908
2016	93.9077
2017	94.81871