| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 | 
                                    
                                    0%
                                 | 
| 0 | 103 | 
                                    
                                    75.2%
                                 | |
| 1 | One minute or less | 5 | 
                                    
                                    3.6%
                                 | 
| 5 | 3 | 
                                    
                                    2.2%
                                 | |
| 10 | 4 | 
                                    
                                    2.9%
                                 | |
| 15 | 1 | 
                                    
                                    0.7%
                                 | |
| 20 | 3 | 
                                    
                                    2.2%
                                 | |
| 30 | 18 | 
                                    
                                    13.1%
                                 | |
| Sysmiss | 226 |