| Value | Category | Cases | |
|---|---|---|---|
| 1 | Not effective at all | 8 | 
                                                                 
                                    
                                    2.9%
                                 
                                                             | 
                                                        
                    
| 2 | 7 | 
                                                                 
                                    
                                    2.5%
                                 
                                                             | 
                                                        
                    |
| 3 | 7 | 
                                                                 
                                    
                                    2.5%
                                 
                                                             | 
                                                        
                    |
| 4 | 6 | 
                                                                 
                                    
                                    2.2%
                                 
                                                             | 
                                                        
                    |
| 5 | 24 | 
                                                                 
                                    
                                    8.7%
                                 
                                                             | 
                                                        
                    |
| 6 | 7 | 
                                                                 
                                    
                                    2.5%
                                 
                                                             | 
                                                        
                    |
| 7 | 17 | 
                                                                 
                                    
                                    6.2%
                                 
                                                             | 
                                                        
                    |
| 8 | 18 | 
                                                                 
                                    
                                    6.5%
                                 
                                                             | 
                                                        
                    |
| 9 | 14 | 
                                                                 
                                    
                                    5.1%
                                 
                                                             | 
                                                        
                    |
| 10 | Very effective | 34 | 
                                                                 
                                    
                                    12.4%
                                 
                                                             | 
                                                        
                    
| 11 | Don't know | 133 | 
                                                                 
                                    
                                    48.4%
                                 
                                                             | 
                                                        
                    
| Sysmiss | 18 |