Year	% net
1973	18.59082
1978	17.14554
1980	18.70052
1981	20.57046
1982	23.85651
1983	29.98929
1984	34.70884
1985	38.96946
1986	41.46913
1987	46.5633
1988	49.16317
1993	49.06123
2000	41.29739
2001	50.13475
2002	49.38625
2003	52.81008
2004	54.41122
2005	57.65405
2006	74.35688
2007	81.83963
2008	92.38812
2009	90.49009
2010	95.37413
2017	94.87551
2018	92.8047