Year	% net
1971	50.52952
1972	55.6204
1973	59.207
1974	59.69965
1975	67.07201
1976	69.397
1977	65.29218
1978	63.49599
1979	61.05338
1980	65.61409
1981	62.40057
1982	68.08045
1983	72.25444
1984	73.97007
1985	76.90945
1986	75.05923
1987	73.90615
1988	74.25073
1989	75.12351
1990	77.31684
1991	77.83846
1992	80.41933
1993	80.00205
1994	78.80144
1995	80.91534
1996	82.75585
1997	81.41419
1998	80.54673
1999	79.17236
2000	81.92398
2001	81.15571
2002	82.64271
2003	87.37437
2004	90.51167
2005	89.33641
2006	86.65017
2008	81.22545
2010	82.61997
2012	90.2793
2013	89.35361
2014	90.23435
2015	91.74513
2016	91.76873
2017	94.47046