Year	% net
1972	80.61804
1973	86.26344
1978	94.86776
1979	95.13012
1980	91.44087
1981	90.05813
1982	89.54815
1983	87.63735
1984	87.42596
1985	89.42158
1999	87.86538
2000	88.42867
2002	90.15669
2003	91.72847
2004	91.97269
2005	90.79131
2006	89.04175
2007	86.07493
2008	83.33206
2010	79.98633
2011	77.41865
2012	74.35083
2013	74.04019
2016	76.24419
2017	79.54806
2018	80.17565