Year	% net
1986	47.10249
1987	47.94386
1988	47.44333
1989	45.88711
1990	46.72132
1991	46.10101
1994	47.71012
1995	49.32331
1996	51.15111
1999	54.98575
2000	56.09204
2002	60.41548
2003	63.26205
2004	65.15369
2005	66.67768
2006	67.83849
2007	68.93457
2008	69.60395
2009	69.68225
2010	70.08479
2011	70.65515
2012	71.82661
2013	75.56968
2014	77.66257
2015	80.02575
2016	81.22278
2017	81.15596