| Value | Category | Cases | |
|---|---|---|---|
| 1 | Not effective at all | 3 | 
                                    
                                    1.3%
                                 | 
| 2 | 2 | 
                                    
                                    0.9%
                                 | |
| 3 | 6 | 
                                    
                                    2.7%
                                 | |
| 4 | 11 | 
                                    
                                    4.9%
                                 | |
| 5 | 21 | 
                                    
                                    9.3%
                                 | |
| 6 | 23 | 
                                    
                                    10.2%
                                 | |
| 7 | 20 | 
                                    
                                    8.8%
                                 | |
| 8 | 36 | 
                                    
                                    15.9%
                                 | |
| 9 | 29 | 
                                    
                                    12.8%
                                 | |
| 10 | Very effective | 75 | 
                                    
                                    33.2%
                                 | 
| 11 | Don't know | 45 | |
| Sysmiss | 48 |