Year	% net
1971	53.89117
1972	53.54469
1973	53.24587
1978	68.6232
1979	69.21718
1980	71.96876
1992	47.29107
1994	66.74448
1996	91.9655
1997	89.08834
1999	81.77246
2000	82.00457
2001	82.03189
2006	88.71929
2007	88.97308
2008	87.51241
2009	84.58073
2010	87.37731
2011	86.35335
2012	86.53257
2013	85.04221
2014	83.835
2015	86.52941