| Value | Category | Cases | |
|---|---|---|---|
| -99 | 14 | 
                                    
                                    4.9%
                                 | |
| 1 | Not effective at all | 13 | 
                                    
                                    4.5%
                                 | 
| 2 | 13 | 
                                    
                                    4.5%
                                 | |
| 3 | 15 | 
                                    
                                    5.2%
                                 | |
| 4 | 19 | 
                                    
                                    6.6%
                                 | |
| 5 | 24 | 
                                    
                                    8.3%
                                 | |
| 6 | 12 | 
                                    
                                    4.2%
                                 | |
| 7 | 17 | 
                                    
                                    5.9%
                                 | |
| 8 | 22 | 
                                    
                                    7.6%
                                 | |
| 9 | 10 | 
                                    
                                    3.5%
                                 | |
| 10 | Very effective | 16 | 
                                    
                                    5.6%
                                 | 
| 11 | Don't know | 113 | 
                                    
                                    39.2%
                                 | 
| Sysmiss | 38 |