| Value | Category | Cases | |
|---|---|---|---|
| 1 | Not effective at all | 6 | 
                                    
                                    3.7%
                                 | 
| 2 | 11 | 
                                    
                                    6.7%
                                 | |
| 3 | 10 | 
                                    
                                    6.1%
                                 | |
| 4 | 10 | 
                                    
                                    6.1%
                                 | |
| 5 | 19 | 
                                    
                                    11.7%
                                 | |
| 6 | 14 | 
                                    
                                    8.6%
                                 | |
| 7 | 16 | 
                                    
                                    9.8%
                                 | |
| 8 | 16 | 
                                    
                                    9.8%
                                 | |
| 9 | 12 | 
                                    
                                    7.4%
                                 | |
| 10 | Very effective | 16 | 
                                    
                                    9.8%
                                 | 
| 11 | Don't know | 32 | 
                                    
                                    19.6%
                                 | 
| 12 | Not applicable | 1 | 
                                    
                                    0.6%
                                 | 
| Sysmiss | 44 |