| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 183 | 
                                    
                                    13.9%
                                 | 
| -4 | Too many to count | 919 | 
                                    
                                    69.8%
                                 | 
| 0 | 5 | 
                                    
                                    0.4%
                                 | |
| 1 | 6 | 
                                    
                                    0.5%
                                 | |
| 2 | 13 | 
                                    
                                    1%
                                 | |
| 3 | 33 | 
                                    
                                    2.5%
                                 | |
| 4 | 45 | 
                                    
                                    3.4%
                                 | |
| 5 | 41 | 
                                    
                                    3.1%
                                 | |
| 6 | 11 | 
                                    
                                    0.8%
                                 | |
| 7 | 2 | 
                                    
                                    0.2%
                                 | |
| 8 | 4 | 
                                    
                                    0.3%
                                 | |
| 10 | 16 | 
                                    
                                    1.2%
                                 | |
| 12 | 1 | 
                                    
                                    0.1%
                                 | |
| 15 | 5 | 
                                    
                                    0.4%
                                 | |
| 20 | 11 | 
                                    
                                    0.8%
                                 | |
| 30 | 5 | 
                                    
                                    0.4%
                                 | |
| 40 | 1 | 
                                    
                                    0.1%
                                 | |
| 50 | 5 | 
                                    
                                    0.4%
                                 | |
| 72 | 1 | 
                                    
                                    0.1%
                                 | |
| 100 | 5 | 
                                    
                                    0.4%
                                 | |
| 120 | 1 | 
                                    
                                    0.1%
                                 | |
| 500 | 1 | 
                                    
                                    0.1%
                                 | |
| 1000 | 2 | 
                                    
                                    0.2%
                                 | |
| 1650 | 1 | 
                                    
                                    0.1%
                                 | |
| Sysmiss | 99 |