| Value | Category | Cases | |
|---|---|---|---|
| 1 | Not effective at all | 2 | 
                                    
                                    1.9%
                                 | 
| 2 | 4 | 
                                    
                                    3.9%
                                 | |
| 3 | 3 | 
                                    
                                    2.9%
                                 | |
| 4 | 5 | 
                                    
                                    4.9%
                                 | |
| 5 | 11 | 
                                    
                                    10.7%
                                 | |
| 6 | 13 | 
                                    
                                    12.6%
                                 | |
| 7 | 9 | 
                                    
                                    8.7%
                                 | |
| 8 | 11 | 
                                    
                                    10.7%
                                 | |
| 9 | 6 | 
                                    
                                    5.8%
                                 | |
| 10 | Very effective | 4 | 
                                    
                                    3.9%
                                 | 
| 11 | Don't know | 35 | 
                                    
                                    34%
                                 | 
| Sysmiss | 9 |