| Value | Category | Cases | |
|---|---|---|---|
| -99 | 5 | 
                                    
                                    1.3%
                                 | |
| 1 | Not effective at all | 2 | 
                                    
                                    0.5%
                                 | 
| 2 | 2 | 
                                    
                                    0.5%
                                 | |
| 3 | 4 | 
                                    
                                    1%
                                 | |
| 4 | 8 | 
                                    
                                    2.1%
                                 | |
| 5 | 27 | 
                                    
                                    7.1%
                                 | |
| 6 | 33 | 
                                    
                                    8.6%
                                 | |
| 7 | 48 | 
                                    
                                    12.6%
                                 | |
| 8 | 68 | 
                                    
                                    17.8%
                                 | |
| 9 | 21 | 
                                    
                                    5.5%
                                 | |
| 10 | Very effective | 16 | 
                                    
                                    4.2%
                                 | 
| 11 | Don't know | 148 | 
                                    
                                    38.7%
                                 | 
| Sysmiss | 47 |