Year	% net
1971	37.77743
1973	50.50787
1974	49.50979
1975	49.05772
1976	51.64118
1977	53.74466
1978	53.95761
1979	55.06812
1980	53.26981
1981	49.82359
1995	40.90974
1996	39.5881
1997	39.12637
1998	40.34748
1999	39.96501
2000	40.75517
2001	42.80277
2002	42.71066
2003	58.92338
2004	62.38114
2005	65.18964
2006	64.68819
2007	65.63726
2008	65.94929
2009	65.80146
2010	66.63655
2011	68.8941
2012	72.41835
2013	48.90337