Plot of Calls*Date.  Legend: A = 1 obs, B = 2 obs, etc.                                 
                                                                                                                        
      |                                                                                                                 
      |                                                                                                                 
  600 +                                                                                                   A             
      |                                                                                                                 
      |                                                                                                                 
      |                                                                                                                 
      |                                                                                                     A           
N 500 +                                                             A     A                                             
u     |               A                                   A                                                             
m     |                        A                                                                                        
b     |                                                                                                                 
e     |                                    A                                                                      A     
r 400 +                                                                                  A                              
      |                                A                              A                                                 
o     |                              A  A    A                                         A                                
f     |                                                                A                                                
      |                                                                          A                      A               
C 300 +                                              A        A                     A                 A                 
a     |                    A                                     A             A                                        
l     |                                                                                                                 
l     |                                       A  A                           A                                          
s     |                                                                                      A                          
  200 +                  A       A                                                                                      
      |   A                       A                    A                                                                
      |                                                   A                                                     A       
      |                             A                                                                                   
      |      A                                                                                                          
  100 +                                                                                                                 
      |                                                                                                                 
      ---+--------+--------+--------+--------+--------+--------+--------+--------+--------+--------+--------+--------+--
      01JAN94  01FEB94  01MAR94  01APR94  01MAY94  01JUN94  01JUL94  01AUG94  01SEP94  01OCT94  01NOV94  01DEC94 01JAN95
                                                                                                                        
                                                             Date