| Value | Category | Cases | |
|---|---|---|---|
| 1 | Not effective at all | 5 | 
                                    
                                    8.6%
                                 | 
| 2 | 5 | 
                                    
                                    8.6%
                                 | |
| 3 | 3 | 
                                    
                                    5.2%
                                 | |
| 4 | 3 | 
                                    
                                    5.2%
                                 | |
| 5 | 8 | 
                                    
                                    13.8%
                                 | |
| 6 | 5 | 
                                    
                                    8.6%
                                 | |
| 7 | 10 | 
                                    
                                    17.2%
                                 | |
| 8 | 9 | 
                                    
                                    15.5%
                                 | |
| 9 | 8 | 
                                    
                                    13.8%
                                 | |
| 10 | Very effective | 2 | 
                                    
                                    3.4%
                                 | 
| 11 | Don't know | 52 | |
| Sysmiss | 33 |