Chapter 12: Number of machine jams when filling bottles of
shampoo. Data were taken in September 1992.

Col 1: Date.
Col 2: Number of jams.
Col 3: Shift number. 

   3        3       1     
   3        6       2     
   3        5       3    
   4        1       1    
   4        5       2  
   4        4       3        
   5        2       1  
   5        6       2  
   5        5       3  
   6        3       1  
   6        3       2  
   6        4       3  
   7        8       1  
   7       12       2  
   7        3       3  
   8        3       1  
   8        4       2  
   8        7       3  
   9        2       1  
   9        4       2