| Value | Category | Cases | |
|---|---|---|---|
| 1 | months | 0 | 
                                    
                                    0%
                                 | 
| 2 | years | 8 | 
                                    
                                    88.9%
                                 | 
| 9 | special answers | 1 | 
                                    
                                    11.1%
                                 | 
| Sysmiss | 15342 |