Year	% net
1998	52.55712
1999	52.95357
2000	53.98122
2001	54.6834
2002	55.28579
2003	56.18066
2004	57.14436
2005	57.8885
2006	58.61426
2007	59.8615
2008	60.69278
2009	61.29083
2010	62.86385
2011	64.12658
2012	64.47047
2013	66.15774
2014	67.10091
2015	67.12962
2016	67.42127
2017	67.9526
2018	68.12466