Year	% net
1971	61.57229
1972	64.00042
1973	67.47904
1974	70.68263
1975	73.26056
1976	74.99273
1977	75.87551
1978	76.16369
1982	80.2448
1991	76.11952
1992	77.49013
1995	80.87477
1996	80.52582
1997	79.77884
1998	86.24669
1999	87.82838
2000	87.67056
2001	87.6736
2002	88.5078
2003	89.32151
2004	90.56761
2005	90.98434
2006	91.33237
2007	92.95211
2008	92.76846
2009	94.17296
2010	95.39837
2012	97.33072