Year	% net
1971	57.12095
1972	59.67378
1973	62.28035
1974	64.72418
1975	64.5203
1976	72.53122
1977	73.82683
1978	75.4489
1979	89.96211
1980	93.51063
1981	92.72885
1983	88.39691
1985	87.40411
1986	88.10204
1987	89.86442
1988	90.97534
1989	89.92145
1993	78.60533
1996	76.13983
1999	90.0423
2000	88.89713
2003	94.37695
2004	92.99956
2007	92.79598