| Value | Category | Cases | |
|---|---|---|---|
| 1 | Not effective at all | 2 | 
                                                                 
                                    
                                    0.9%
                                 
                                                             | 
                                                        
                    
| 2 | 6 | 
                                                                 
                                    
                                    2.7%
                                 
                                                             | 
                                                        
                    |
| 3 | 14 | 
                                                                 
                                    
                                    6.2%
                                 
                                                             | 
                                                        
                    |
| 4 | 13 | 
                                                                 
                                    
                                    5.8%
                                 
                                                             | 
                                                        
                    |
| 5 | 18 | 
                                                                 
                                    
                                    8%
                                 
                                                             | 
                                                        
                    |
| 6 | 14 | 
                                                                 
                                    
                                    6.2%
                                 
                                                             | 
                                                        
                    |
| 7 | 19 | 
                                                                 
                                    
                                    8.4%
                                 
                                                             | 
                                                        
                    |
| 8 | 16 | 
                                                                 
                                    
                                    7.1%
                                 
                                                             | 
                                                        
                    |
| 9 | 11 | 
                                                                 
                                    
                                    4.9%
                                 
                                                             | 
                                                        
                    |
| 10 | Very effective | 17 | 
                                                                 
                                    
                                    7.5%
                                 
                                                             | 
                                                        
                    
| 11 | Don't know | 96 | 
                                                                 
                                    
                                    42.5%
                                 
                                                             | 
                                                        
                    
| Sysmiss | 11 |