Year	% net
1977	94.63652
1978	96.01222
1985	98.82753
1987	98.46917
1988	98.63856
2005	82.56368
2006	84.50447
2007	82.64389
2008	88.44901
2009	91.54072
2010	88.62022
2011	86.75953
2012	87.12086
2013	86.69654
2014	86.34084
2015	87.98828
2016	89.14081
2017	86.07316
2018	86.02531