| Value | Category | Cases | |
|---|---|---|---|
| 1 | Not effective at all | 2 | 
                                    
                                    3.1%
                                 | 
| 2 | 4 | 
                                    
                                    6.3%
                                 | |
| 3 | 5 | 
                                    
                                    7.8%
                                 | |
| 4 | 2 | 
                                    
                                    3.1%
                                 | |
| 5 | 6 | 
                                    
                                    9.4%
                                 | |
| 6 | 12 | 
                                    
                                    18.8%
                                 | |
| 7 | 13 | 
                                    
                                    20.3%
                                 | |
| 8 | 7 | 
                                    
                                    10.9%
                                 | |
| 9 | 11 | 
                                    
                                    17.2%
                                 | |
| 10 | Very effective | 2 | 
                                    
                                    3.1%
                                 | 
| 11 | Don't know | 49 | |
| Sysmiss | 30 |