| Value | Category | Cases | |
|---|---|---|---|
| -99 | 2 | 
                                    
                                    0.5%
                                 | |
| 1 | Not effective at all | 4 | 
                                    
                                    1.1%
                                 | 
| 2 | 2 | 
                                    
                                    0.5%
                                 | |
| 3 | 3 | 
                                    
                                    0.8%
                                 | |
| 4 | 7 | 
                                    
                                    1.8%
                                 | |
| 5 | 16 | 
                                    
                                    4.2%
                                 | |
| 6 | 39 | 
                                    
                                    10.3%
                                 | |
| 7 | 52 | 
                                    
                                    13.7%
                                 | |
| 8 | 69 | 
                                    
                                    18.2%
                                 | |
| 9 | 45 | 
                                    
                                    11.8%
                                 | |
| 10 | Very effective | 20 | 
                                    
                                    5.3%
                                 | 
| 11 | Don't know | 121 | 
                                    
                                    31.8%
                                 | 
| Sysmiss | 49 |