| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 7 | 
                                    
                                    2.1%
                                 | 
| -4 | Too many to count | 123 | 
                                    
                                    36.8%
                                 | 
| 0 | 39 | 
                                    
                                    11.7%
                                 | |
| 1 | 7 | 
                                    
                                    2.1%
                                 | |
| 2 | 12 | 
                                    
                                    3.6%
                                 | |
| 3 | 25 | 
                                    
                                    7.5%
                                 | |
| 4 | 21 | 
                                    
                                    6.3%
                                 | |
| 5 | 26 | 
                                    
                                    7.8%
                                 | |
| 6 | 11 | 
                                    
                                    3.3%
                                 | |
| 7 | 7 | 
                                    
                                    2.1%
                                 | |
| 8 | 6 | 
                                    
                                    1.8%
                                 | |
| 9 | 1 | 
                                    
                                    0.3%
                                 | |
| 10 | 15 | 
                                    
                                    4.5%
                                 | |
| 11 | 1 | 
                                    
                                    0.3%
                                 | |
| 12 | 1 | 
                                    
                                    0.3%
                                 | |
| 15 | 2 | 
                                    
                                    0.6%
                                 | |
| 18 | 1 | 
                                    
                                    0.3%
                                 | |
| 20 | 5 | 
                                    
                                    1.5%
                                 | |
| 23 | 1 | 
                                    
                                    0.3%
                                 | |
| 28 | 2 | 
                                    
                                    0.6%
                                 | |
| 30 | 5 | 
                                    
                                    1.5%
                                 | |
| 32 | 1 | 
                                    
                                    0.3%
                                 | |
| 33 | 1 | 
                                    
                                    0.3%
                                 | |
| 35 | 2 | 
                                    
                                    0.6%
                                 | |
| 40 | 3 | 
                                    
                                    0.9%
                                 | |
| 50 | 2 | 
                                    
                                    0.6%
                                 | |
| 60 | 1 | 
                                    
                                    0.3%
                                 | |
| 63 | 1 | 
                                    
                                    0.3%
                                 | |
| 64 | 1 | 
                                    
                                    0.3%
                                 | |
| 70 | 1 | 
                                    
                                    0.3%
                                 | |
| 100 | 2 | 
                                    
                                    0.6%
                                 | |
| 273 | 1 | 
                                    
                                    0.3%
                                 | |
| Sysmiss | 29 |