| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 1 | 
                                                                 
                                    
                                    20%
                                 
                                                             | 
                                                        
                    
| 30 | 3 | 
                                                                 
                                    
                                    60%
                                 
                                                             | 
                                                        
                    |
| 45 | 1 | 
                                                                 
                                    
                                    20%
                                 
                                                             | 
                                                        
                    |
| Sysmiss | 151 |