Year	% net
1976	74.12853
1977	75.25144
1978	75.94666
1979	76.42906
1980	77.07952
1981	77.14461
1982	77.51494
1983	78.01707
1984	78.41859
1985	79.10291
1986	80.33742
1987	80.90738
1988	81.08754
1989	81.40195
1990	81.54465
1991	82.60871
1992	84.13616
1993	86.85979
1994	89.15218
1995	89.35535
1996	89.80216
1997	89.4256
1998	87.43316
1999	87.08596
2000	87.47144
2001	88.28076
2002	88.86846
2003	89.40814
2004	90.51846
2005	91.649
2006	92.03121
2007	91.51074
2008	91.97556
2009	91.84057
2010	91.95209
2011	91.36812
2012	91.12635
2013	90.49134
2014	90.29469
2015	90.541
2016	90.90451
2017	90.98786
2018	91.01464