Year	% net
1972	81.14138
1979	97.03223
1993	98.75371
1994	98.63792
1995	98.31477
1996	98.36753
1997	98.71485
1998	99.41359
1999	99.78745
2000	99.70392
2001	99.61892
2002	99.262
2003	98.52116
2004	97.57685
2005	97.1783
2006	96.6628
2007	97.26075
2008	97.71417
2009	97.87074
2010	98.21163
2011	98.48757
2012	99.0129
2013	99.03438
2014	99.36498
2015	99.11706
2016	99.05594
2017	98.62944