| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 138 | 
                                    
                                    34.8%
                                 | 
| 0 | 4 | 
                                    
                                    1%
                                 | |
| 1 | 68 | 
                                    
                                    17.2%
                                 | |
| 2 | 61 | 
                                    
                                    15.4%
                                 | |
| 3 | 24 | 
                                    
                                    6.1%
                                 | |
| 4 | 9 | 
                                    
                                    2.3%
                                 | |
| 5 | 23 | 
                                    
                                    5.8%
                                 | |
| 6 | 1 | 
                                    
                                    0.3%
                                 | |
| 8 | 2 | 
                                    
                                    0.5%
                                 | |
| 9 | 5 | 
                                    
                                    1.3%
                                 | |
| 10 | 28 | 
                                    
                                    7.1%
                                 | |
| 12 | 4 | 
                                    
                                    1%
                                 | |
| 15 | 18 | 
                                    
                                    4.5%
                                 | |
| 20 | 4 | 
                                    
                                    1%
                                 | |
| 25 | 1 | 
                                    
                                    0.3%
                                 | |
| 30 | 1 | 
                                    
                                    0.3%
                                 | |
| 36 | 1 | 
                                    
                                    0.3%
                                 | |
| 40 | 1 | 
                                    
                                    0.3%
                                 | |
| 50 | 1 | 
                                    
                                    0.3%
                                 | |
| 98 | 1 | 
                                    
                                    0.3%
                                 | |
| 100 | 1 | 
                                    
                                    0.3%
                                 | |
| Sysmiss | 249 |