Year	% net
1986	58.86643
1987	59.18704
1988	59.27749
1989	58.98873
1990	59.24334
1991	59.70192
1992	60.17237
1993	60.06922
1994	60.63553
1995	61.44071
1996	62.49479
1997	62.80015
1998	64.09322
1999	64.52519
2000	65.38891
2001	66.29725
2002	67.32007
2003	65.8224
2004	66.99694
2005	67.90555
2006	68.37099
2007	68.6504
2008	70.97578
2009	71.96324
2010	72.38443
2011	72.76949
2012	72.55697
2013	75.89555
2014	76.21968
2015	76.65285
2016	77.41567
2017	77.28509
2018	77.43196