Year	% net
1970	63.78913
1983	75.06557
1998	87.92355
2000	88.89193
2001	89.59586
2002	91.19483
2003	93.2033
2010	94.39786
2011	93.92888
2012	93.04104
2013	90.61104
2014	88.43302
2015	86.06177
2016	84.90831
2017	80.63027
2018	81.41932