| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 41 | 
                                    
                                    22.9%
                                 | 
| 0 | Less than one day | 40 | 
                                    
                                    22.3%
                                 | 
| 1 | 24 | 
                                    
                                    13.4%
                                 | |
| 2 | 13 | 
                                    
                                    7.3%
                                 | |
| 3 | 10 | 
                                    
                                    5.6%
                                 | |
| 4 | 8 | 
                                    
                                    4.5%
                                 | |
| 5 | 10 | 
                                    
                                    5.6%
                                 | |
| 6 | 3 | 
                                    
                                    1.7%
                                 | |
| 7 | 9 | 
                                    
                                    5%
                                 | |
| 8 | 1 | 
                                    
                                    0.6%
                                 | |
| 10 | 7 | 
                                    
                                    3.9%
                                 | |
| 12 | 1 | 
                                    
                                    0.6%
                                 | |
| 13 | 1 | 
                                    
                                    0.6%
                                 | |
| 14 | 2 | 
                                    
                                    1.1%
                                 | |
| 21 | 3 | 
                                    
                                    1.7%
                                 | |
| 40 | 1 | 
                                    
                                    0.6%
                                 | |
| 61 | 1 | 
                                    
                                    0.6%
                                 | |
| 67 | 1 | 
                                    
                                    0.6%
                                 | |
| 74 | 1 | 
                                    
                                    0.6%
                                 | |
| 90 | 1 | 
                                    
                                    0.6%
                                 | |
| 97 | 1 | 
                                    
                                    0.6%
                                 | |
| Sysmiss | 421 |