| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 4 | 
                                    
                                    1.4%
                                 | 
| -4 | Too many to count | 72 | 
                                    
                                    25.9%
                                 | 
| 0 | 10 | 
                                    
                                    3.6%
                                 | |
| 1 | 4 | 
                                    
                                    1.4%
                                 | |
| 2 | 9 | 
                                    
                                    3.2%
                                 | |
| 3 | 25 | 
                                    
                                    9%
                                 | |
| 4 | 20 | 
                                    
                                    7.2%
                                 | |
| 5 | 49 | 
                                    
                                    17.6%
                                 | |
| 6 | 13 | 
                                    
                                    4.7%
                                 | |
| 7 | 3 | 
                                    
                                    1.1%
                                 | |
| 8 | 6 | 
                                    
                                    2.2%
                                 | |
| 9 | 1 | 
                                    
                                    0.4%
                                 | |
| 10 | 35 | 
                                    
                                    12.6%
                                 | |
| 12 | 2 | 
                                    
                                    0.7%
                                 | |
| 15 | 5 | 
                                    
                                    1.8%
                                 | |
| 16 | 1 | 
                                    
                                    0.4%
                                 | |
| 20 | 6 | 
                                    
                                    2.2%
                                 | |
| 25 | 3 | 
                                    
                                    1.1%
                                 | |
| 30 | 2 | 
                                    
                                    0.7%
                                 | |
| 50 | 1 | 
                                    
                                    0.4%
                                 | |
| 58 | 1 | 
                                    
                                    0.4%
                                 | |
| 60 | 1 | 
                                    
                                    0.4%
                                 | |
| 65 | 1 | 
                                    
                                    0.4%
                                 | |
| 100 | 1 | 
                                    
                                    0.4%
                                 | |
| 300 | 2 | 
                                    
                                    0.7%
                                 | |
| 400 | 1 | 
                                    
                                    0.4%
                                 | |
| Sysmiss | 124 |