| Value | Category | Cases | |
|---|---|---|---|
| 1 | Not effective at all | 3 | 
                                    
                                    2.9%
                                 | 
| 2 | 3 | 
                                    
                                    2.9%
                                 | |
| 3 | 3 | 
                                    
                                    2.9%
                                 | |
| 4 | 8 | 
                                    
                                    7.8%
                                 | |
| 5 | 8 | 
                                    
                                    7.8%
                                 | |
| 6 | 8 | 
                                    
                                    7.8%
                                 | |
| 7 | 15 | 
                                    
                                    14.7%
                                 | |
| 8 | 13 | 
                                    
                                    12.7%
                                 | |
| 9 | 2 | 
                                    
                                    2%
                                 | |
| 10 | Very effective | 5 | 
                                    
                                    4.9%
                                 | 
| 11 | Don't know | 34 | 
                                    
                                    33.3%
                                 | 
| Sysmiss | 10 |