| Value | Category | Cases | |
|---|---|---|---|
| 0 | no | 6406 | 
                                                                 
                                    
                                    99.3%
                                 
                                                             | 
                                                        
                    
| 1 | yes | 23 | 
                                                                 
                                    
                                    0.4%
                                 
                                                             | 
                                                        
                    
| 8 | don't know | 12 | 
                                                                 
                                    
                                    0.2%
                                 
                                                             | 
                                                        
                    
| 9 | 7 | 
                                                                 
                                    
                                    0.1%
                                 
                                                             | 
                                                        
                    |
| 11 | .Z | 12306 |