| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 17 | 
                                    
                                    3.7%
                                 | 
| 0 | 14 | 
                                    
                                    3%
                                 | |
| 1 | 118 | 
                                    
                                    25.4%
                                 | |
| 2 | 150 | 
                                    
                                    32.3%
                                 | |
| 3 | 73 | 
                                    
                                    15.7%
                                 | |
| 4 | 31 | 
                                    
                                    6.7%
                                 | |
| 5 | 33 | 
                                    
                                    7.1%
                                 | |
| 6 | 5 | 
                                    
                                    1.1%
                                 | |
| 7 | 2 | 
                                    
                                    0.4%
                                 | |
| 8 | 1 | 
                                    
                                    0.2%
                                 | |
| 10 | 8 | 
                                    
                                    1.7%
                                 | |
| 12 | 1 | 
                                    
                                    0.2%
                                 | |
| 15 | 8 | 
                                    
                                    1.7%
                                 | |
| 20 | 1 | 
                                    
                                    0.2%
                                 | |
| 40 | 2 | 
                                    
                                    0.4%
                                 | |
| 50 | 1 | 
                                    
                                    0.2%
                                 | |
| Sysmiss | 951 |