| Value | Category | Cases | |
|---|---|---|---|
| 1 | ONCE | 971 | 
                                    
                                    8.5%
                                 | 
| 2 | MORE THAN ONCE | 127 | 
                                    
                                    1.1%
                                 | 
| 9 | NO RESPONSE | 1 | 
                                    
                                    0%
                                 | 
| Sysmiss | 10365 | 
                                    
                                    90.4%
                                 |