| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 2 | 
                                    
                                    2.2%
                                 | 
| 0 | 1 | 
                                    
                                    1.1%
                                 | |
| 1 | 1 | 
                                    
                                    1.1%
                                 | |
| 2 | 14 | 
                                    
                                    15.6%
                                 | |
| 3 | 15 | 
                                    
                                    16.7%
                                 | |
| 4 | 8 | 
                                    
                                    8.9%
                                 | |
| 5 | 14 | 
                                    
                                    15.6%
                                 | |
| 6 | 10 | 
                                    
                                    11.1%
                                 | |
| 8 | 2 | 
                                    
                                    2.2%
                                 | |
| 10 | 5 | 
                                    
                                    5.6%
                                 | |
| 12 | 3 | 
                                    
                                    3.3%
                                 | |
| 15 | 2 | 
                                    
                                    2.2%
                                 | |
| 20 | 2 | 
                                    
                                    2.2%
                                 | |
| 24 | 1 | 
                                    
                                    1.1%
                                 | |
| 26 | 1 | 
                                    
                                    1.1%
                                 | |
| 30 | 9 | 
                                    
                                    10%
                                 | |
| Sysmiss | 274 |