| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 28 | 
                                    
                                    10.1%
                                 | 
| 0 | 56 | 
                                    
                                    20.2%
                                 | |
| 1 | 106 | 
                                    
                                    38.3%
                                 | |
| 2 | 25 | 
                                    
                                    9%
                                 | |
| 3 | 12 | 
                                    
                                    4.3%
                                 | |
| 4 | 12 | 
                                    
                                    4.3%
                                 | |
| 5 | 19 | 
                                    
                                    6.9%
                                 | |
| 6 | 2 | 
                                    
                                    0.7%
                                 | |
| 7 | 1 | 
                                    
                                    0.4%
                                 | |
| 8 | 2 | 
                                    
                                    0.7%
                                 | |
| 10 | 7 | 
                                    
                                    2.5%
                                 | |
| 15 | 1 | 
                                    
                                    0.4%
                                 | |
| 18 | 1 | 
                                    
                                    0.4%
                                 | |
| 30 | 2 | 
                                    
                                    0.7%
                                 | |
| 60 | 2 | 
                                    
                                    0.7%
                                 | |
| 200 | 1 | 
                                    
                                    0.4%
                                 | |
| Sysmiss | 678 |