| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 7 | 
                                    
                                    5.8%
                                 | 
| 0 | Less than one day | 11 | 
                                    
                                    9.2%
                                 | 
| 1 | 16 | 
                                    
                                    13.3%
                                 | |
| 2 | 22 | 
                                    
                                    18.3%
                                 | |
| 3 | 17 | 
                                    
                                    14.2%
                                 | |
| 4 | 4 | 
                                    
                                    3.3%
                                 | |
| 5 | 4 | 
                                    
                                    3.3%
                                 | |
| 6 | 1 | 
                                    
                                    0.8%
                                 | |
| 7 | 10 | 
                                    
                                    8.3%
                                 | |
| 8 | 1 | 
                                    
                                    0.8%
                                 | |
| 9 | 1 | 
                                    
                                    0.8%
                                 | |
| 10 | 4 | 
                                    
                                    3.3%
                                 | |
| 14 | 6 | 
                                    
                                    5%
                                 | |
| 15 | 1 | 
                                    
                                    0.8%
                                 | |
| 20 | 1 | 
                                    
                                    0.8%
                                 | |
| 28 | 2 | 
                                    
                                    1.7%
                                 | |
| 30 | 5 | 
                                    
                                    4.2%
                                 | |
| 40 | 1 | 
                                    
                                    0.8%
                                 | |
| 60 | 2 | 
                                    
                                    1.7%
                                 | |
| 62 | 1 | 
                                    
                                    0.8%
                                 | |
| 65 | 1 | 
                                    
                                    0.8%
                                 | |
| 75 | 1 | 
                                    
                                    0.8%
                                 | |
| 180 | 1 | 
                                    
                                    0.8%
                                 | |
| Sysmiss | 282 |