| Value | Category | Cases | |
|---|---|---|---|
| -99 | 2 | 
                                    
                                    0.7%
                                 | |
| 1 | Not effective at all | 1 | 
                                    
                                    0.3%
                                 | 
| 2 | 5 | 
                                    
                                    1.7%
                                 | |
| 3 | 8 | 
                                    
                                    2.7%
                                 | |
| 4 | 23 | 
                                    
                                    7.9%
                                 | |
| 5 | 46 | 
                                    
                                    15.8%
                                 | |
| 6 | 38 | 
                                    
                                    13%
                                 | |
| 7 | 34 | 
                                    
                                    11.6%
                                 | |
| 8 | 27 | 
                                    
                                    9.2%
                                 | |
| 9 | 11 | 
                                    
                                    3.8%
                                 | |
| 10 | Very effective | 5 | 
                                    
                                    1.7%
                                 | 
| 11 | Don't know | 92 | 
                                    
                                    31.5%
                                 | 
| Sysmiss | 9 |