| Value | Category | Cases | |
|---|---|---|---|
| 1 | Not effective at all | 1 | 
                                                                 
                                    
                                    0.8%
                                 
                                                             | 
                                                        
                    
| 2 | 5 | 
                                                                 
                                    
                                    4%
                                 
                                                             | 
                                                        
                    |
| 3 | 6 | 
                                                                 
                                    
                                    4.8%
                                 
                                                             | 
                                                        
                    |
| 4 | 14 | 
                                                                 
                                    
                                    11.2%
                                 
                                                             | 
                                                        
                    |
| 5 | 16 | 
                                                                 
                                    
                                    12.8%
                                 
                                                             | 
                                                        
                    |
| 6 | 18 | 
                                                                 
                                    
                                    14.4%
                                 
                                                             | 
                                                        
                    |
| 7 | 20 | 
                                                                 
                                    
                                    16%
                                 
                                                             | 
                                                        
                    |
| 8 | 26 | 
                                                                 
                                    
                                    20.8%
                                 
                                                             | 
                                                        
                    |
| 9 | 16 | 
                                                                 
                                    
                                    12.8%
                                 
                                                             | 
                                                        
                    |
| 10 | Very effective | 3 | 
                                                                 
                                    
                                    2.4%
                                 
                                                             | 
                                                        
                    
| 11 | Don't know | 0 | 
                                                                 
                                    
                                    0%
                                 
                                                             | 
                                                        
                    
| Sysmiss | 250 |