| Value | Category | Cases | |
|---|---|---|---|
| 1 | Not effective at all | 3 | 
                                                                 
                                    
                                    1.4%
                                 
                                                             | 
                                                        
                    
| 2 | 3 | 
                                                                 
                                    
                                    1.4%
                                 
                                                             | 
                                                        
                    |
| 3 | 5 | 
                                                                 
                                    
                                    2.3%
                                 
                                                             | 
                                                        
                    |
| 4 | 16 | 
                                                                 
                                    
                                    7.3%
                                 
                                                             | 
                                                        
                    |
| 5 | 28 | 
                                                                 
                                    
                                    12.8%
                                 
                                                             | 
                                                        
                    |
| 6 | 16 | 
                                                                 
                                    
                                    7.3%
                                 
                                                             | 
                                                        
                    |
| 7 | 16 | 
                                                                 
                                    
                                    7.3%
                                 
                                                             | 
                                                        
                    |
| 8 | 19 | 
                                                                 
                                    
                                    8.7%
                                 
                                                             | 
                                                        
                    |
| 9 | 9 | 
                                                                 
                                    
                                    4.1%
                                 
                                                             | 
                                                        
                    |
| 10 | Very effective | 13 | 
                                                                 
                                    
                                    5.9%
                                 
                                                             | 
                                                        
                    
| 11 | Don't know | 91 | 
                                                                 
                                    
                                    41.6%
                                 
                                                             | 
                                                        
                    
| Sysmiss | 18 |