| Value | Category | Cases | |
|---|---|---|---|
| 1 | Not effective at all | 8 | 
                                    
                                    2.7%
                                 | 
| 2 | 9 | 
                                    
                                    3%
                                 | |
| 3 | 8 | 
                                    
                                    2.7%
                                 | |
| 4 | 19 | 
                                    
                                    6.4%
                                 | |
| 5 | 70 | 
                                    
                                    23.6%
                                 | |
| 6 | 36 | 
                                    
                                    12.1%
                                 | |
| 7 | 21 | 
                                    
                                    7.1%
                                 | |
| 8 | 23 | 
                                    
                                    7.7%
                                 | |
| 9 | 5 | 
                                    
                                    1.7%
                                 | |
| 10 | Very effective | 8 | 
                                    
                                    2.7%
                                 | 
| 11 | Don't know | 90 | 
                                    
                                    30.3%
                                 | 
| Sysmiss | 4 |