Year	% net
1971	68.60957
1972	68.57248
1974	68.16386
1975	70.17104
1976	70.52792
1999	88.47397
2000	88.42819
2002	88.40836
2003	88.4619
2004	88.60349
2005	89.18387
2006	89.26828
2007	88.21249
2008	88.16806
2009	87.93998
2010	86.79411
2011	86.61554
2012	86.14129
2013	86.22208
2014	86.55112
2015	86.71155
2016	87.37319
2017	87.00131