Year	% net
1970	11.21915
1971	11.54199
1972	12.99253
1974	17.29354
1975	19.28111
1976	20.54427
1977	22.24896
1998	34.65212
1999	32.85493
2000	31.12904
2001	32.32801
2002	33.73414
2003	32.95422
2004	37.26517
2005	35.74311
2006	31.48725
2007	32.8932
2009	36.179
2010	37.06153
2011	39.58057
2012	40.13429
2013	39.00495
2014	40.49563
2015	41.69996