| Value | Category | Cases | |
|---|---|---|---|
| 1 | Not effective at all | 4 | 
                                                                 
                                    
                                    1.8%
                                 
                                                             | 
                                                        
                    
| 2 | 7 | 
                                                                 
                                    
                                    3.2%
                                 
                                                             | 
                                                        
                    |
| 3 | 9 | 
                                                                 
                                    
                                    4.1%
                                 
                                                             | 
                                                        
                    |
| 4 | 8 | 
                                                                 
                                    
                                    3.6%
                                 
                                                             | 
                                                        
                    |
| 5 | 12 | 
                                                                 
                                    
                                    5.5%
                                 
                                                             | 
                                                        
                    |
| 6 | 13 | 
                                                                 
                                    
                                    5.9%
                                 
                                                             | 
                                                        
                    |
| 7 | 15 | 
                                                                 
                                    
                                    6.8%
                                 
                                                             | 
                                                        
                    |
| 8 | 9 | 
                                                                 
                                    
                                    4.1%
                                 
                                                             | 
                                                        
                    |
| 9 | 2 | 
                                                                 
                                    
                                    0.9%
                                 
                                                             | 
                                                        
                    |
| 10 | Very effective | 7 | 
                                                                 
                                    
                                    3.2%
                                 
                                                             | 
                                                        
                    
| 11 | Don't know | 134 | 
                                                                 
                                    
                                    60.9%
                                 
                                                             | 
                                                        
                    
| Sysmiss | 17 |