| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 | 
                                                                 
                                    
                                    0%
                                 
                                                             | 
                                                        
                    
| 2 | 1 | 
                                                                 
                                    
                                    2.9%
                                 
                                                             | 
                                                        
                    |
| 10 | 6 | 
                                                                 
                                    
                                    17.6%
                                 
                                                             | 
                                                        
                    |
| 15 | 2 | 
                                                                 
                                    
                                    5.9%
                                 
                                                             | 
                                                        
                    |
| 20 | 8 | 
                                                                 
                                    
                                    23.5%
                                 
                                                             | 
                                                        
                    |
| 30 | 15 | 
                                                                 
                                    
                                    44.1%
                                 
                                                             | 
                                                        
                    |
| 40 | 1 | 
                                                                 
                                    
                                    2.9%
                                 
                                                             | 
                                                        
                    |
| 45 | 1 | 
                                                                 
                                    
                                    2.9%
                                 
                                                             | 
                                                        
                    |
| Sysmiss | 1484 |