| Value | Category | Cases | |
|---|---|---|---|
| -99 | Don't know | 1 | 
                                    
                                    0.4%
                                 | 
| -9 | Don't know (spontaneous) | 3 | 
                                    
                                    1.3%
                                 | 
| 1 | Increase | 20 | 
                                    
                                    8.6%
                                 | 
| 2 | Remain the same | 97 | 
                                    
                                    41.6%
                                 | 
| 3 | Decrease | 112 | 
                                    
                                    48.1%
                                 | 
| Sysmiss | 127 |