| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know | 0 | 
                                    
                                    0%
                                 | 
| -8 | Refusal | 0 | 
                                    
                                    0%
                                 | 
| -7 | Does not apply | 0 | 
                                    
                                    0%
                                 | 
| 2013 | 162 | 
                                    
                                    100%
                                 | |
| Sysmiss | 793 |