| Value | Category | Cases | |
|---|---|---|---|
| 1 | Not effective at all | 2 | 
                                    
                                    2.9%
                                 | 
| 2 | 4 | 
                                    
                                    5.8%
                                 | |
| 3 | 1 | 
                                    
                                    1.4%
                                 | |
| 4 | 5 | 
                                    
                                    7.2%
                                 | |
| 5 | 13 | 
                                    
                                    18.8%
                                 | |
| 6 | 11 | 
                                    
                                    15.9%
                                 | |
| 7 | 14 | 
                                    
                                    20.3%
                                 | |
| 8 | 14 | 
                                    
                                    20.3%
                                 | |
| 9 | 4 | 
                                    
                                    5.8%
                                 | |
| 10 | Very effective | 1 | 
                                    
                                    1.4%
                                 | 
| -99 | 3 | ||
| 11 | Don't know | 63 | |
| Sysmiss | 24 |