78.00%
80.00 +
¦ ___________________
70.00 + ___________________ 60.80% 60.30%
¦ ___________________
60.00 + __________________________________________________________
¦ __________________________________________________________
50.00 + __________________________________________________________
¦ __________________________________________________________
40.00 + __________________________________________________________
¦ __________________________________________________________
30.00 + __________________________________________________________
¦ __________________________________________________________
20.00 + __________________________________________________________
¦ __________________________________________________________
10.00 + __________________________________________________________
¦ __________________________________________________________
0.00 +--__________________________________________________________
1991 1993 1994