| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 25 | 
                                                                 
                                    
                                    21.9%
                                 
                                                             | 
                                                        
                    
| 1 | One hour or less | 3 | 
                                                                 
                                    
                                    2.6%
                                 
                                                             | 
                                                        
                    
| 2 | 1 | 
                                                                 
                                    
                                    0.9%
                                 
                                                             | 
                                                        
                    |
| 3 | 1 | 
                                                                 
                                    
                                    0.9%
                                 
                                                             | 
                                                        
                    |
| 5 | 1 | 
                                                                 
                                    
                                    0.9%
                                 
                                                             | 
                                                        
                    |
| 12 | 1 | 
                                                                 
                                    
                                    0.9%
                                 
                                                             | 
                                                        
                    |
| 16 | 1 | 
                                                                 
                                    
                                    0.9%
                                 
                                                             | 
                                                        
                    |
| 24 | 4 | 
                                                                 
                                    
                                    3.5%
                                 
                                                             | 
                                                        
                    |
| 30 | 5 | 
                                                                 
                                    
                                    4.4%
                                 
                                                             | 
                                                        
                    |
| 36 | 1 | 
                                                                 
                                    
                                    0.9%
                                 
                                                             | 
                                                        
                    |
| 40 | 39 | 
                                                                 
                                    
                                    34.2%
                                 
                                                             | 
                                                        
                    |
| 45 | 1 | 
                                                                 
                                    
                                    0.9%
                                 
                                                             | 
                                                        
                    |
| 48 | 1 | 
                                                                 
                                    
                                    0.9%
                                 
                                                             | 
                                                        
                    |
| 50 | 7 | 
                                                                 
                                    
                                    6.1%
                                 
                                                             | 
                                                        
                    |
| 60 | 9 | 
                                                                 
                                    
                                    7.9%
                                 
                                                             | 
                                                        
                    |
| 72 | 1 | 
                                                                 
                                    
                                    0.9%
                                 
                                                             | 
                                                        
                    |
| 80 | 4 | 
                                                                 
                                    
                                    3.5%
                                 
                                                             | 
                                                        
                    |
| 100 | 3 | 
                                                                 
                                    
                                    2.6%
                                 
                                                             | 
                                                        
                    |
| 120 | 1 | 
                                                                 
                                    
                                    0.9%
                                 
                                                             | 
                                                        
                    |
| 144 | 1 | 
                                                                 
                                    
                                    0.9%
                                 
                                                             | 
                                                        
                    |
| 160 | 1 | 
                                                                 
                                    
                                    0.9%
                                 
                                                             | 
                                                        
                    |
| 200 | 2 | 
                                                                 
                                    
                                    1.8%
                                 
                                                             | 
                                                        
                    |
| 240 | 1 | 
                                                                 
                                    
                                    0.9%
                                 
                                                             |