| Value | Category | Cases | |
|---|---|---|---|
| 1 | Not effective at all | 3 | 
                                    
                                    2.9%
                                 | 
| 2 | 4 | 
                                    
                                    3.9%
                                 | |
| 3 | 6 | 
                                    
                                    5.8%
                                 | |
| 4 | 11 | 
                                    
                                    10.7%
                                 | |
| 5 | 8 | 
                                    
                                    7.8%
                                 | |
| 6 | 11 | 
                                    
                                    10.7%
                                 | |
| 7 | 9 | 
                                    
                                    8.7%
                                 | |
| 8 | 5 | 
                                    
                                    4.9%
                                 | |
| 9 | 3 | 
                                    
                                    2.9%
                                 | |
| 10 | Very effective | 1 | 
                                    
                                    1%
                                 | 
| 11 | Don't know | 42 | 
                                    
                                    40.8%
                                 | 
| Sysmiss | 9 |