| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 | 
                                    
                                    0%
                                 | 
| -8 | Refusal (spontaneous) | 0 | 
                                    
                                    0%
                                 | 
| -7 | Does not apply | 269 | 
                                    
                                    99.3%
                                 | 
| 1 | One year or less | 0 | 
                                    
                                    0%
                                 | 
| 10 | 1 | 
                                    
                                    0.4%
                                 | |
| 12 | 1 | 
                                    
                                    0.4%
                                 | |
| Sysmiss | 684 |