Year	% net
1971	87.50555
1972	88.76435
1973	88.82329
1974	90.21617
1975	91.99724
1976	93.85934
1977	95.28625
1978	94.97205
1979	95.46696
1980	99.33509
1981	98.88392
1982	98.72351
1983	98.51133
1984	97.75575
1985	96.53091
1995	95.01585
1996	94.16782