Year	% net
1974	14.95668
1997	45.08283
1999	49.55606
2000	56.75201
2001	64.78663
2002	64.64982
2003	65.11575
2004	67.60049
2005	70.45934
2006	73.28097
2007	75.35689
2008	75.74826
2009	73.42324
2010	78.07046
2011	81.47034
2012	79.5176
2013	85.38763
2014	86.51644
2015	85.78301
2016	84.77001
2017	86.04436