| Value | Category | Cases | |
|---|---|---|---|
| 1 | once | 124 | 
                                                                 
                                    
                                    93.2%
                                 
                                                             | 
                                                        
                    
| 2 | more than once | 9 | 
                                                                 
                                    
                                    6.8%
                                 
                                                             | 
                                                        
                    
| Sysmiss | 79 |