| Value | Category | Cases | |
|---|---|---|---|
| 1 | Not effective at all | 3 | 
                                    
                                    7.5%
                                 | 
| 2 | 5 | 
                                    
                                    12.5%
                                 | |
| 3 | 7 | 
                                    
                                    17.5%
                                 | |
| 4 | 1 | 
                                    
                                    2.5%
                                 | |
| 5 | 4 | 
                                    
                                    10%
                                 | |
| 6 | 3 | 
                                    
                                    7.5%
                                 | |
| 7 | 1 | 
                                    
                                    2.5%
                                 | |
| 8 | 8 | 
                                    
                                    20%
                                 | |
| 9 | 7 | 
                                    
                                    17.5%
                                 | |
| 10 | Very effective | 1 | 
                                    
                                    2.5%
                                 | 
| 11 | Don't know | 71 | |
| Sysmiss | 32 |