| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 2 | 
                                                                 
                                    
                                    4.1%
                                 
                                                             | 
                                                        
                    
| 0 | 23 | 
                                                                 
                                    
                                    46.9%
                                 
                                                             | 
                                                        
                    |
| 1 | One minute or less | 4 | 
                                                                 
                                    
                                    8.2%
                                 
                                                             | 
                                                        
                    
| 5 | 1 | 
                                                                 
                                    
                                    2%
                                 
                                                             | 
                                                        
                    |
| 10 | 3 | 
                                                                 
                                    
                                    6.1%
                                 
                                                             | 
                                                        
                    |
| 15 | 4 | 
                                                                 
                                    
                                    8.2%
                                 
                                                             | 
                                                        
                    |
| 20 | 1 | 
                                                                 
                                    
                                    2%
                                 
                                                             | 
                                                        
                    |
| 25 | 1 | 
                                                                 
                                    
                                    2%
                                 
                                                             | 
                                                        
                    |
| 30 | 9 | 
                                                                 
                                    
                                    18.4%
                                 
                                                             | 
                                                        
                    |
| 40 | 1 | 
                                                                 
                                    
                                    2%
                                 
                                                             | 
                                                        
                    |
| Sysmiss | 560 |