| Value | Category | Cases | |
|---|---|---|---|
| 0 | no: source known | 932 | 
                                                                 
                                    
                                    5%
                                 
                                                             | 
                                                        
                    
| 1 | yes: no source known | 17820 | 
                                                                 
                                    
                                    95%
                                 
                                                             | 
                                                        
                    
| 9 | 2 | 
                                                                 
                                    
                                    0%
                                 
                                                             |