| Value | Category | Cases | |
|---|---|---|---|
| 1 | Not effective at all | 4 | 
                                    
                                    1.4%
                                 | 
| 2 | 6 | 
                                    
                                    2%
                                 | |
| 3 | 10 | 
                                    
                                    3.4%
                                 | |
| 4 | 22 | 
                                    
                                    7.5%
                                 | |
| 5 | 53 | 
                                    
                                    18.1%
                                 | |
| 6 | 44 | 
                                    
                                    15%
                                 | |
| 7 | 25 | 
                                    
                                    8.5%
                                 | |
| 8 | 21 | 
                                    
                                    7.2%
                                 | |
| 9 | 7 | 
                                    
                                    2.4%
                                 | |
| 10 | Very effective | 8 | 
                                    
                                    2.7%
                                 | 
| 11 | Don't know | 93 | 
                                    
                                    31.7%
                                 | 
| Sysmiss | 8 |