| Value | Category | Cases | |
|---|---|---|---|
| 1 | Once | 33 | 
                                                                 
                                    
                                    0.2%
                                 
                                                             | 
                                                        
                    
| 2 | Twice | 9 | 
                                                                 
                                    
                                    0.1%
                                 
                                                             | 
                                                        
                    
| 3 | Three times | 6 | 
                                                                 
                                    
                                    0%
                                 
                                                             | 
                                                        
                    
| 4 | Four times | 1 | 
                                                                 
                                    
                                    0%
                                 
                                                             | 
                                                        
                    
| 5 | More | 8 | 
                                                                 
                                    
                                    0.1%
                                 
                                                             | 
                                                        
                    
| 6 | Never | 13176 | 
                                                                 
                                    
                                    99.6%
                                 
                                                             | 
                                                        
                    
| Sysmiss | 835 |