| Value | Category | Cases | |
|---|---|---|---|
| -99 | 5 | 
                                    
                                    1.3%
                                 | |
| 1 | Not effective at all | 2 | 
                                    
                                    0.5%
                                 | 
| 2 | 1 | 
                                    
                                    0.3%
                                 | |
| 3 | 5 | 
                                    
                                    1.3%
                                 | |
| 4 | 6 | 
                                    
                                    1.6%
                                 | |
| 5 | 26 | 
                                    
                                    6.8%
                                 | |
| 6 | 27 | 
                                    
                                    7%
                                 | |
| 7 | 37 | 
                                    
                                    9.7%
                                 | |
| 8 | 45 | 
                                    
                                    11.7%
                                 | |
| 9 | 26 | 
                                    
                                    6.8%
                                 | |
| 10 | Very effective | 11 | 
                                    
                                    2.9%
                                 | 
| 11 | Don't know | 192 | 
                                    
                                    50.1%
                                 | 
| Sysmiss | 46 |