| Value | Category | Cases | |
|---|---|---|---|
| -99 | 1 | 
                                    
                                    0.3%
                                 | |
| 1 | Not effective at all | 2 | 
                                    
                                    0.7%
                                 | 
| 2 | 0 | 
                                    
                                    0%
                                 | |
| 3 | 7 | 
                                    
                                    2.4%
                                 | |
| 4 | 9 | 
                                    
                                    3%
                                 | |
| 5 | 23 | 
                                    
                                    7.8%
                                 | |
| 6 | 39 | 
                                    
                                    13.2%
                                 | |
| 7 | 42 | 
                                    
                                    14.2%
                                 | |
| 8 | 50 | 
                                    
                                    16.9%
                                 | |
| 9 | 25 | 
                                    
                                    8.4%
                                 | |
| 10 | Very effective | 9 | 
                                    
                                    3%
                                 | 
| 11 | Don't know | 89 | 
                                    
                                    30.1%
                                 | 
| Sysmiss | 5 |