Year	% net
1977	99.1299
1994	97.33665
1996	97.9898
1997	98.47849
1998	99.41332
1999	98.79555
2000	98.82721
2001	99.14985
2002	99.20209
2003	98.20419
2004	96.5557
2005	96.76546
2006	97.22027
2007	98.03954
2008	99.1549
2009	99.6124
2010	99.2208
2011	98.72088
2012	98.15848
2013	98.03622
2014	98.12777
2015	98.56708
2016	99.45437
2017	99.83367