| Value | Category | Cases | |
|---|---|---|---|
| 1 | Not effective at all | 8 | 
                                    
                                    1.3%
                                 | 
| 2 | 15 | 
                                    
                                    2.5%
                                 | |
| 3 | 25 | 
                                    
                                    4.2%
                                 | |
| 4 | 24 | 
                                    
                                    4%
                                 | |
| 5 | 54 | 
                                    
                                    9%
                                 | |
| 6 | 94 | 
                                    
                                    15.7%
                                 | |
| 7 | 97 | 
                                    
                                    16.2%
                                 | |
| 8 | 78 | 
                                    
                                    13.1%
                                 | |
| 9 | 41 | 
                                    
                                    6.9%
                                 | |
| 10 | Very effective | 25 | 
                                    
                                    4.2%
                                 | 
| 11 | Don't know | 136 | 
                                    
                                    22.8%
                                 | 
| Sysmiss | 27 |