| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 | 
                                                                 
                                    
                                    0%
                                 
                                                             | 
                                                        
                    
| -7 | Does not apply (spontaneous) | 0 | 
                                                                 
                                    
                                    0%
                                 
                                                             | 
                                                        
                    
| 0 | Less than one day | 9 | 
                                                                 
                                    
                                    20.9%
                                 
                                                             | 
                                                        
                    
| 1 | 15 | 
                                                                 
                                    
                                    34.9%
                                 
                                                             | 
                                                        
                    |
| 2 | 19 | 
                                                                 
                                    
                                    44.2%
                                 
                                                             | 
                                                        
                    |
| Sysmiss | 113 |