| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 11 | 
                                                                 
                                    
                                    3.3%
                                 
                                                             | 
                                                        
                    
| -4 | Too many to count | 198 | 
                                                                 
                                    
                                    59.6%
                                 
                                                             | 
                                                        
                    
| 0 | 8 | 
                                                                 
                                    
                                    2.4%
                                 
                                                             | 
                                                        
                    |
| 1 | 4 | 
                                                                 
                                    
                                    1.2%
                                 
                                                             | 
                                                        
                    |
| 2 | 15 | 
                                                                 
                                    
                                    4.5%
                                 
                                                             | 
                                                        
                    |
| 3 | 14 | 
                                                                 
                                    
                                    4.2%
                                 
                                                             | 
                                                        
                    |
| 4 | 7 | 
                                                                 
                                    
                                    2.1%
                                 
                                                             | 
                                                        
                    |
| 5 | 20 | 
                                                                 
                                    
                                    6%
                                 
                                                             | 
                                                        
                    |
| 6 | 15 | 
                                                                 
                                    
                                    4.5%
                                 
                                                             | 
                                                        
                    |
| 7 | 2 | 
                                                                 
                                    
                                    0.6%
                                 
                                                             | 
                                                        
                    |
| 8 | 4 | 
                                                                 
                                    
                                    1.2%
                                 
                                                             | 
                                                        
                    |
| 9 | 4 | 
                                                                 
                                    
                                    1.2%
                                 
                                                             | 
                                                        
                    |
| 10 | 12 | 
                                                                 
                                    
                                    3.6%
                                 
                                                             | 
                                                        
                    |
| 11 | 1 | 
                                                                 
                                    
                                    0.3%
                                 
                                                             | 
                                                        
                    |
| 12 | 1 | 
                                                                 
                                    
                                    0.3%
                                 
                                                             | 
                                                        
                    |
| 15 | 6 | 
                                                                 
                                    
                                    1.8%
                                 
                                                             | 
                                                        
                    |
| 20 | 4 | 
                                                                 
                                    
                                    1.2%
                                 
                                                             | 
                                                        
                    |
| 22 | 1 | 
                                                                 
                                    
                                    0.3%
                                 
                                                             | 
                                                        
                    |
| 25 | 1 | 
                                                                 
                                    
                                    0.3%
                                 
                                                             | 
                                                        
                    |
| 30 | 1 | 
                                                                 
                                    
                                    0.3%
                                 
                                                             | 
                                                        
                    |
| 35 | 1 | 
                                                                 
                                    
                                    0.3%
                                 
                                                             | 
                                                        
                    |
| 40 | 1 | 
                                                                 
                                    
                                    0.3%
                                 
                                                             | 
                                                        
                    |
| 80 | 1 | 
                                                                 
                                    
                                    0.3%
                                 
                                                             | 
                                                        
                    |
| Sysmiss | 43 |