| Value | Category | Cases | |
|---|---|---|---|
| 1 | Not effective at all | 1 | 
                                    
                                    0.9%
                                 | 
| 2 | 6 | 
                                    
                                    5.7%
                                 | |
| 3 | 4 | 
                                    
                                    3.8%
                                 | |
| 4 | 6 | 
                                    
                                    5.7%
                                 | |
| 5 | 10 | 
                                    
                                    9.4%
                                 | |
| 6 | 6 | 
                                    
                                    5.7%
                                 | |
| 7 | 17 | 
                                    
                                    16%
                                 | |
| 8 | 6 | 
                                    
                                    5.7%
                                 | |
| 9 | 1 | 
                                    
                                    0.9%
                                 | |
| 10 | Very effective | 2 | 
                                    
                                    1.9%
                                 | 
| 11 | Don't know | 47 | 
                                    
                                    44.3%
                                 | 
| Sysmiss | 6 |