| Value | Category | Cases | |
|---|---|---|---|
| 1 | Not effective at all | 2 | 
                                    
                                    0.9%
                                 | 
| 2 | 6 | 
                                    
                                    2.6%
                                 | |
| 3 | 5 | 
                                    
                                    2.2%
                                 | |
| 4 | 12 | 
                                    
                                    5.2%
                                 | |
| 5 | 17 | 
                                    
                                    7.4%
                                 | |
| 6 | 21 | 
                                    
                                    9.2%
                                 | |
| 7 | 38 | 
                                    
                                    16.6%
                                 | |
| 8 | 28 | 
                                    
                                    12.2%
                                 | |
| 9 | 30 | 
                                    
                                    13.1%
                                 | |
| 10 | Very effective | 70 | 
                                    
                                    30.6%
                                 | 
| 11 | Don't know | 43 | |
| Sysmiss | 47 |