| Value | Category | Cases | |
|---|---|---|---|
| -99 | 1 | 
                                                                 
                                    
                                    0.4%
                                 
                                                             | 
                                                        
                    |
| 1 | Not effective at all | 3 | 
                                                                 
                                    
                                    1.3%
                                 
                                                             | 
                                                        
                    
| 2 | 8 | 
                                                                 
                                    
                                    3.6%
                                 
                                                             | 
                                                        
                    |
| 3 | 6 | 
                                                                 
                                    
                                    2.7%
                                 
                                                             | 
                                                        
                    |
| 4 | 11 | 
                                                                 
                                    
                                    4.9%
                                 
                                                             | 
                                                        
                    |
| 5 | 24 | 
                                                                 
                                    
                                    10.7%
                                 
                                                             | 
                                                        
                    |
| 6 | 18 | 
                                                                 
                                    
                                    8%
                                 
                                                             | 
                                                        
                    |
| 7 | 16 | 
                                                                 
                                    
                                    7.1%
                                 
                                                             | 
                                                        
                    |
| 8 | 21 | 
                                                                 
                                    
                                    9.3%
                                 
                                                             | 
                                                        
                    |
| 9 | 10 | 
                                                                 
                                    
                                    4.4%
                                 
                                                             | 
                                                        
                    |
| 10 | Very effective | 9 | 
                                                                 
                                    
                                    4%
                                 
                                                             | 
                                                        
                    
| 11 | Don't know | 98 | 
                                                                 
                                    
                                    43.6%
                                 
                                                             | 
                                                        
                    
| Sysmiss | 12 |