| Value | Category | Cases | |
|---|---|---|---|
| 1 | Not effective at all | 2 | 
                                                                 
                                    
                                    1.2%
                                 
                                                             | 
                                                        
                    
| 2 | 4 | 
                                                                 
                                    
                                    2.4%
                                 
                                                             | 
                                                        
                    |
| 3 | 7 | 
                                                                 
                                    
                                    4.2%
                                 
                                                             | 
                                                        
                    |
| 4 | 4 | 
                                                                 
                                    
                                    2.4%
                                 
                                                             | 
                                                        
                    |
| 5 | 16 | 
                                                                 
                                    
                                    9.5%
                                 
                                                             | 
                                                        
                    |
| 6 | 21 | 
                                                                 
                                    
                                    12.5%
                                 
                                                             | 
                                                        
                    |
| 7 | 19 | 
                                                                 
                                    
                                    11.3%
                                 
                                                             | 
                                                        
                    |
| 8 | 10 | 
                                                                 
                                    
                                    6%
                                 
                                                             | 
                                                        
                    |
| 9 | 4 | 
                                                                 
                                    
                                    2.4%
                                 
                                                             | 
                                                        
                    |
| 10 | Very effective | 5 | 
                                                                 
                                    
                                    3%
                                 
                                                             | 
                                                        
                    
| 11 | Don't know | 76 | 
                                                                 
                                    
                                    45.2%
                                 
                                                             | 
                                                        
                    
| Sysmiss | 18 |