Year	% net
1991	22.20481
1992	22.14214
1993	22.2499
1994	22.85873
1995	23.60075
1996	23.79204
1997	24.01738
1998	24.56148
1999	24.77815
2000	25.72943
2001	26.42205
2002	26.75585
2003	28.39825
2004	30.21112
2005	30.85191
2006	31.97246
2007	32.37373
2008	33.81246
2009	34.84787
2010	35.5295
2011	35.93476
2012	36.6002
2013	35.62697
2014	36.03712
2015	36.51341
2016	36.85874
2017	37.63171
2018	37.62826