Year	% net
1998	66.36746
1999	67.44824
2000	68.22952
2001	69.06052
2002	69.28454
2003	69.8354
2004	71.1363
2005	72.62438
2006	73.70264
2007	74.85362
2008	75.97171
2009	78.05906
2010	79.78083
2011	80.79711
2012	80.28708
2013	82.13076
2014	84.45315
2015	84.13048
2016	84.12704
2017	83.60366
2018	83.92186