Year	% net
1973	4.90081
1974	9.40158
1975	14.566
1976	16.67843
1978	22.56069
1979	25.96712
1981	31.59413
1982	34.7856
1983	39.89616
1984	46.75114
1985	51.55054
1986	60.53199
1987	61.70437
1988	61.7355
1989	63.09117
1990	64.80003
1991	66.56478
1992	68.20155
1993	72.6001
1994	74.53744
1995	75.82932
1996	77.89322
1997	79.31814
1998	80.14487
1999	81.57312
2000	82.31775
2001	83.77984
2002	83.10216
2003	81.26801
2011	96.17882