Year	% net
1981	68.96957
1982	64.94606
1983	64.41072
1985	58.60795
1986	57.37544
1987	55.55926
1988	53.7258
1989	53.52845
1990	52.78702
1991	52.01735
1992	52.00352
1993	51.40762
1994	50.393
1995	50.21043
1996	50.32388
1997	50.83809
1998	50.42278
1999	50.93254
2000	54.43399
2001	58.43572
2002	72.78572
2003	80.9404
2004	85.58811
2005	90.27577
2006	96.33842
2008	98.72642
2010	93.04912
2012	88.83323
2013	85.40375
2014	85.39817
2016	85.38355
2017	85.18502
2018	82.84537