Year	% net
1991	25.72152
1992	25.60095
1993	25.75484
1994	26.65085
1995	27.45429
1996	27.58539
1997	27.76034
1998	28.31834
1999	28.5171
2000	29.37545
2001	30.29341
2002	30.6804
2003	32.26753
2004	34.39812
2005	34.91618
2006	36.20758
2007	36.44406
2008	38.08392
2009	39.18735
2010	39.79255
2011	40.14866
2012	40.72932
2013	39.59504
2014	40.09394
2015	40.37925
2016	40.72137
2017	41.40841
2018	41.39649