| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 | 
                                                                 
                                    
                                    0%
                                 
                                                             | 
                                                        
                    
| 0 | Less than 1 hour | 31 | 
                                                                 
                                    
                                    20.1%
                                 
                                                             | 
                                                        
                    
| 1 | 27 | 
                                                                 
                                    
                                    17.5%
                                 
                                                             | 
                                                        
                    |
| 2 | 28 | 
                                                                 
                                    
                                    18.2%
                                 
                                                             | 
                                                        
                    |
| 3 | 19 | 
                                                                 
                                    
                                    12.3%
                                 
                                                             | 
                                                        
                    |
| 4 | 11 | 
                                                                 
                                    
                                    7.1%
                                 
                                                             | 
                                                        
                    |
| 5 | 20 | 
                                                                 
                                    
                                    13%
                                 
                                                             | 
                                                        
                    |
| 6 | 7 | 
                                                                 
                                    
                                    4.5%
                                 
                                                             | 
                                                        
                    |
| 10 | 3 | 
                                                                 
                                    
                                    1.9%
                                 
                                                             | 
                                                        
                    |
| 12 | 1 | 
                                                                 
                                    
                                    0.6%
                                 
                                                             | 
                                                        
                    |
| 15 | 2 | 
                                                                 
                                    
                                    1.3%
                                 
                                                             | 
                                                        
                    |
| 20 | 1 | 
                                                                 
                                    
                                    0.6%
                                 
                                                             | 
                                                        
                    |
| 24 | 1 | 
                                                                 
                                    
                                    0.6%
                                 
                                                             | 
                                                        
                    |
| 36 | 1 | 
                                                                 
                                    
                                    0.6%
                                 
                                                             | 
                                                        
                    |
| 48 | 1 | 
                                                                 
                                    
                                    0.6%
                                 
                                                             | 
                                                        
                    |
| 150 | 1 | 
                                                                 
                                    
                                    0.6%
                                 
                                                             | 
                                                        
                    |
| Sysmiss | 226 |