| Value | Category | Cases | |
|---|---|---|---|
| 9997 | More than 9997 | 0 | 
                                    
                                    0%
                                 | 
| 9998 | Don't know | 0 | 
                                    
                                    0%
                                 | 
| 9999 | Missing | 35 | 
                                    
                                    100%
                                 |