Year	% net
1992	94.45572
1993	93.41655
1994	93.06256
1995	91.829
1996	92.12041
1997	91.57325
1998	91.59311
1999	91.94323
2000	91.17819
2001	91.87537
2002	92.82763
2003	94.81058
2004	94.22083
2005	92.75084
2006	92.79129
2007	92.91735
2008	93.0729
2009	92.65775
2010	93.29969
2011	93.46094
2012	93.25988
2013	93.64177
2014	93.40826
2015	93.6759
2016	93.82713
2017	91.98788
2018	91.81915