| Value | Category | Cases | |
|---|---|---|---|
| 1 | Not effective at all | 2 | 
                                                                 
                                    
                                    1.6%
                                 
                                                             | 
                                                        
                    
| 2 | 3 | 
                                                                 
                                    
                                    2.4%
                                 
                                                             | 
                                                        
                    |
| 3 | 3 | 
                                                                 
                                    
                                    2.4%
                                 
                                                             | 
                                                        
                    |
| 4 | 6 | 
                                                                 
                                    
                                    4.9%
                                 
                                                             | 
                                                        
                    |
| 5 | 9 | 
                                                                 
                                    
                                    7.3%
                                 
                                                             | 
                                                        
                    |
| 6 | 18 | 
                                                                 
                                    
                                    14.6%
                                 
                                                             | 
                                                        
                    |
| 7 | 29 | 
                                                                 
                                    
                                    23.6%
                                 
                                                             | 
                                                        
                    |
| 8 | 24 | 
                                                                 
                                    
                                    19.5%
                                 
                                                             | 
                                                        
                    |
| 9 | 21 | 
                                                                 
                                    
                                    17.1%
                                 
                                                             | 
                                                        
                    |
| 10 | Extremely effective | 8 | 
                                                                 
                                    
                                    6.5%
                                 
                                                             | 
                                                        
                    
| 11 | Don't know | 13 | |
| Sysmiss | 2 |