| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 8 | 
                                    
                                    17%
                                 | 
| 0 | Less than one day | 1 | 
                                    
                                    2.1%
                                 | 
| 2 | 1 | 
                                    
                                    2.1%
                                 | |
| 4 | 1 | 
                                    
                                    2.1%
                                 | |
| 5 | 2 | 
                                    
                                    4.3%
                                 | |
| 6 | 1 | 
                                    
                                    2.1%
                                 | |
| 7 | 2 | 
                                    
                                    4.3%
                                 | |
| 10 | 1 | 
                                    
                                    2.1%
                                 | |
| 12 | 1 | 
                                    
                                    2.1%
                                 | |
| 13 | 1 | 
                                    
                                    2.1%
                                 | |
| 14 | 1 | 
                                    
                                    2.1%
                                 | |
| 15 | 6 | 
                                    
                                    12.8%
                                 | |
| 16 | 1 | 
                                    
                                    2.1%
                                 | |
| 20 | 2 | 
                                    
                                    4.3%
                                 | |
| 21 | 1 | 
                                    
                                    2.1%
                                 | |
| 25 | 4 | 
                                    
                                    8.5%
                                 | |
| 30 | 7 | 
                                    
                                    14.9%
                                 | |
| 32 | 1 | 
                                    
                                    2.1%
                                 | |
| 35 | 1 | 
                                    
                                    2.1%
                                 | |
| 60 | 2 | 
                                    
                                    4.3%
                                 | |
| 75 | 1 | 
                                    
                                    2.1%
                                 | |
| 120 | 1 | 
                                    
                                    2.1%
                                 | |
| Sysmiss | 1369 |