Year	% net
1971	96.66083
1973	95.61789
1974	95.03012
1975	97.49052
1976	98.35892
1982	99.05941
1983	97.89896
1984	96.17074
1985	96.45473
1986	97.25597
1987	97.91632
1988	98.66307
1989	98.77965
1990	98.27587
1991	97.68312
1992	97.44872
1993	97.00772
1994	96.71711
1995	95.27062
1996	95.79718
1997	95.55864
1998	95.67511
1999	95.67654
2000	95.90952
2003	96.398
2004	96.66264
2011	97.98201
2012	98.2361
2017	96.74048