| Value | Category | Cases | |
|---|---|---|---|
| 1 | Not effective at all | 5 | 
                                    
                                    2.5%
                                 | 
| 2 | 6 | 
                                    
                                    3%
                                 | |
| 3 | 13 | 
                                    
                                    6.6%
                                 | |
| 4 | 12 | 
                                    
                                    6.1%
                                 | |
| 5 | 21 | 
                                    
                                    10.7%
                                 | |
| 6 | 20 | 
                                    
                                    10.2%
                                 | |
| 7 | 30 | 
                                    
                                    15.2%
                                 | |
| 8 | 27 | 
                                    
                                    13.7%
                                 | |
| 9 | 22 | 
                                    
                                    11.2%
                                 | |
| 10 | Very effective | 41 | 
                                    
                                    20.8%
                                 | 
| 11 | Don't know | 72 | |
| Sysmiss | 50 |