| Value | Category | Cases | |
|---|---|---|---|
| -99 | 11 | 
                                    
                                    3.7%
                                 | |
| 1 | Not effective at all | 13 | 
                                    
                                    4.4%
                                 | 
| 2 | 17 | 
                                    
                                    5.7%
                                 | |
| 3 | 14 | 
                                    
                                    4.7%
                                 | |
| 4 | 19 | 
                                    
                                    6.4%
                                 | |
| 5 | 24 | 
                                    
                                    8.1%
                                 | |
| 6 | 12 | 
                                    
                                    4%
                                 | |
| 7 | 30 | 
                                    
                                    10.1%
                                 | |
| 8 | 18 | 
                                    
                                    6.1%
                                 | |
| 9 | 13 | 
                                    
                                    4.4%
                                 | |
| 10 | Very effective | 20 | 
                                    
                                    6.7%
                                 | 
| 11 | Don't know | 106 | 
                                    
                                    35.7%
                                 | 
| Sysmiss | 29 |