| Value | Category | Cases | |
|---|---|---|---|
| 1 | Not effective at all | 1 | 
                                                                 
                                    
                                    0.8%
                                 
                                                             | 
                                                        
                    
| 2 | 2 | 3 | 
                                                                 
                                    
                                    2.4%
                                 
                                                             | 
                                                        
                    
| 3 | 3 | 6 | 
                                                                 
                                    
                                    4.8%
                                 
                                                             | 
                                                        
                    
| 4 | 4 | 10 | 
                                                                 
                                    
                                    8%
                                 
                                                             | 
                                                        
                    
| 5 | 5 | 10 | 
                                                                 
                                    
                                    8%
                                 
                                                             | 
                                                        
                    
| 6 | 6 | 9 | 
                                                                 
                                    
                                    7.2%
                                 
                                                             | 
                                                        
                    
| 7 | 7 | 13 | 
                                                                 
                                    
                                    10.4%
                                 
                                                             | 
                                                        
                    
| 8 | 8 | 10 | 
                                                                 
                                    
                                    8%
                                 
                                                             | 
                                                        
                    
| 9 | 9 | 5 | 
                                                                 
                                    
                                    4%
                                 
                                                             | 
                                                        
                    
| 10 | Very effective | 10 | 
                                                                 
                                    
                                    8%
                                 
                                                             | 
                                                        
                    
| 11 | Don't know | 48 | 
                                                                 
                                    
                                    38.4%
                                 
                                                             | 
                                                        
                    
| Sysmiss | 21 |