| Value | Category | Cases | |
|---|---|---|---|
| -99 | 6 | 
                                    
                                    1.6%
                                 | |
| 1 | Not effective at all | 2 | 
                                    
                                    0.5%
                                 | 
| 2 | 2 | 
                                    
                                    0.5%
                                 | |
| 3 | 2 | 
                                    
                                    0.5%
                                 | |
| 4 | 2 | 
                                    
                                    0.5%
                                 | |
| 5 | 14 | 
                                    
                                    3.7%
                                 | |
| 6 | 39 | 
                                    
                                    10.3%
                                 | |
| 7 | 52 | 
                                    
                                    13.7%
                                 | |
| 8 | 85 | 
                                    
                                    22.4%
                                 | |
| 9 | 41 | 
                                    
                                    10.8%
                                 | |
| 10 | Very effective | 25 | 
                                    
                                    6.6%
                                 | 
| 11 | Don't know | 110 | 
                                    
                                    28.9%
                                 | 
| Sysmiss | 49 |