| Value | Category | Cases | |
|---|---|---|---|
| -99 | Don't know | 0 | 
                                    
                                    0%
                                 | 
| -9 | Don't know (spontaneous) | 0 | 
                                    
                                    0%
                                 | 
| 0 | 20 | 
                                    
                                    36.4%
                                 | |
| 1 | 8 | 
                                    
                                    14.5%
                                 | |
| 2 | 4 | 
                                    
                                    7.3%
                                 | |
| 3 | 4 | 
                                    
                                    7.3%
                                 | |
| 4 | 2 | 
                                    
                                    3.6%
                                 | |
| 5 | 5 | 
                                    
                                    9.1%
                                 | |
| 6 | 2 | 
                                    
                                    3.6%
                                 | |
| 7 | 1 | 
                                    
                                    1.8%
                                 | |
| 9 | 1 | 
                                    
                                    1.8%
                                 | |
| 10 | 1 | 
                                    
                                    1.8%
                                 | |
| 13 | 1 | 
                                    
                                    1.8%
                                 | |
| 18 | 1 | 
                                    
                                    1.8%
                                 | |
| 20 | 2 | 
                                    
                                    3.6%
                                 | |
| 23 | 1 | 
                                    
                                    1.8%
                                 | |
| 40 | 1 | 
                                    
                                    1.8%
                                 | |
| 180 | 1 | 
                                    
                                    1.8%
                                 | |
| Sysmiss | 187 |