| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 5 | 
                                    
                                    1.6%
                                 | 
| 0 | 42 | 
                                    
                                    13.5%
                                 | |
| 1 | 24 | 
                                    
                                    7.7%
                                 | |
| 2 | 12 | 
                                    
                                    3.9%
                                 | |
| 3 | 3 | 
                                    
                                    1%
                                 | |
| 4 | 1 | 
                                    
                                    0.3%
                                 | |
| 7 | 1 | 
                                    
                                    0.3%
                                 | |
| 8 | 2 | 
                                    
                                    0.6%
                                 | |
| 10 | 3 | 
                                    
                                    1%
                                 | |
| 15 | 1 | 
                                    
                                    0.3%
                                 | |
| 16 | 1 | 
                                    
                                    0.3%
                                 | |
| 17 | 1 | 
                                    
                                    0.3%
                                 | |
| 20 | 2 | 
                                    
                                    0.6%
                                 | |
| 24 | 1 | 
                                    
                                    0.3%
                                 | |
| 25 | 5 | 
                                    
                                    1.6%
                                 | |
| 30 | 2 | 
                                    
                                    0.6%
                                 | |
| 33 | 4 | 
                                    
                                    1.3%
                                 | |
| 40 | 1 | 
                                    
                                    0.3%
                                 | |
| 49 | 1 | 
                                    
                                    0.3%
                                 | |
| 50 | 22 | 
                                    
                                    7.1%
                                 | |
| 51 | 1 | 
                                    
                                    0.3%
                                 | |
| 60 | 1 | 
                                    
                                    0.3%
                                 | |
| 67 | 1 | 
                                    
                                    0.3%
                                 | |
| 70 | 1 | 
                                    
                                    0.3%
                                 | |
| 75 | 4 | 
                                    
                                    1.3%
                                 | |
| 80 | 1 | 
                                    
                                    0.3%
                                 | |
| 90 | 1 | 
                                    
                                    0.3%
                                 | |
| 97 | 1 | 
                                    
                                    0.3%
                                 | |
| 99 | 1 | 
                                    
                                    0.3%
                                 | |
| 100 | 165 | 
                                    
                                    53.1%
                                 | |
| Sysmiss | 644 |