| Value | Category | Cases | |
|---|---|---|---|
| -99 | 2 | 
                                    
                                    0.3%
                                 | |
| 1 | Not effective at all | 7 | 
                                    
                                    1.1%
                                 | 
| 2 | 8 | 
                                    
                                    1.3%
                                 | |
| 3 | 16 | 
                                    
                                    2.6%
                                 | |
| 4 | 29 | 
                                    
                                    4.7%
                                 | |
| 5 | 70 | 
                                    
                                    11.4%
                                 | |
| 6 | 90 | 
                                    
                                    14.7%
                                 | |
| 7 | 86 | 
                                    
                                    14%
                                 | |
| 8 | 83 | 
                                    
                                    13.5%
                                 | |
| 9 | 48 | 
                                    
                                    7.8%
                                 | |
| 10 | Very effective | 28 | 
                                    
                                    4.6%
                                 | 
| 11 | Don't know | 146 | 
                                    
                                    23.8%
                                 | 
| Sysmiss | 11 |