| Value | Category | Cases | |
|---|---|---|---|
| 1 | Not effective at all | 1 | 
                                    
                                    0.9%
                                 | 
| 2 | 6 | 
                                    
                                    5.4%
                                 | |
| 3 | 6 | 
                                    
                                    5.4%
                                 | |
| 4 | 7 | 
                                    
                                    6.3%
                                 | |
| 5 | 21 | 
                                    
                                    18.8%
                                 | |
| 6 | 10 | 
                                    
                                    8.9%
                                 | |
| 7 | 21 | 
                                    
                                    18.8%
                                 | |
| 8 | 24 | 
                                    
                                    21.4%
                                 | |
| 9 | 12 | 
                                    
                                    10.7%
                                 | |
| 10 | Very effective | 4 | 
                                    
                                    3.6%
                                 | 
| 11 | Don't know | 21 | |
| Sysmiss | 10 |