| Value | Category | Cases | |
|---|---|---|---|
| -99 | 6 | 
                                    
                                    1.6%
                                 | |
| 1 | Not effective at all | 2 | 
                                    
                                    0.5%
                                 | 
| 2 | 2 | 
                                    
                                    0.5%
                                 | |
| 3 | 1 | 
                                    
                                    0.3%
                                 | |
| 4 | 3 | 
                                    
                                    0.8%
                                 | |
| 5 | 23 | 
                                    
                                    6%
                                 | |
| 6 | 26 | 
                                    
                                    6.8%
                                 | |
| 7 | 50 | 
                                    
                                    13.1%
                                 | |
| 8 | 72 | 
                                    
                                    18.8%
                                 | |
| 9 | 45 | 
                                    
                                    11.8%
                                 | |
| 10 | Very effective | 24 | 
                                    
                                    6.3%
                                 | 
| 11 | Don't know | 128 | 
                                    
                                    33.5%
                                 | 
| Sysmiss | 47 |