| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 2 | 
                                                                 
                                    
                                    1.2%
                                 
                                                             | 
                                                        
                    
| 1 | One hour or less | 5 | 
                                                                 
                                    
                                    3.1%
                                 
                                                             | 
                                                        
                    
| 2 | 8 | 
                                                                 
                                    
                                    4.9%
                                 
                                                             | 
                                                        
                    |
| 3 | 4 | 
                                                                 
                                    
                                    2.5%
                                 
                                                             | 
                                                        
                    |
| 4 | 5 | 
                                                                 
                                    
                                    3.1%
                                 
                                                             | 
                                                        
                    |
| 5 | 4 | 
                                                                 
                                    
                                    2.5%
                                 
                                                             | 
                                                        
                    |
| 6 | 3 | 
                                                                 
                                    
                                    1.8%
                                 
                                                             | 
                                                        
                    |
| 8 | 2 | 
                                                                 
                                    
                                    1.2%
                                 
                                                             | 
                                                        
                    |
| 10 | 4 | 
                                                                 
                                    
                                    2.5%
                                 
                                                             | 
                                                        
                    |
| 12 | 3 | 
                                                                 
                                    
                                    1.8%
                                 
                                                             | 
                                                        
                    |
| 14 | 6 | 
                                                                 
                                    
                                    3.7%
                                 
                                                             | 
                                                        
                    |
| 16 | 7 | 
                                                                 
                                    
                                    4.3%
                                 
                                                             | 
                                                        
                    |
| 17 | 1 | 
                                                                 
                                    
                                    0.6%
                                 
                                                             | 
                                                        
                    |
| 18 | 4 | 
                                                                 
                                    
                                    2.5%
                                 
                                                             | 
                                                        
                    |
| 19 | 1 | 
                                                                 
                                    
                                    0.6%
                                 
                                                             | 
                                                        
                    |
| 20 | 10 | 
                                                                 
                                    
                                    6.1%
                                 
                                                             | 
                                                        
                    |
| 21 | 2 | 
                                                                 
                                    
                                    1.2%
                                 
                                                             | 
                                                        
                    |
| 22 | 23 | 
                                                                 
                                    
                                    14.1%
                                 
                                                             | 
                                                        
                    |
| 23 | 69 | 
                                                                 
                                    
                                    42.3%
                                 
                                                             | 
                                                        
                    |
| Sysmiss | 1269 |