Year	% net
1971	55.85945
1973	56.13542
1980	65.29528
1982	63.78167
1983	64.39848
1984	62.46133
1985	67.88859
1986	66.60693
1987	67.98531
1988	68.44308
1989	66.4416
1990	68.23713
1991	70.45706
1992	74.32614
1993	75.00464
1994	75.95502
1995	74.50483
1999	79.206
2000	81.96585
2001	84.84078
2002	90.52104
2006	96.58327
2007	96.45125
2008	97.19175
2010	95.96627