| Value | Category | Cases | |
|---|---|---|---|
| -99 | 7 | 
                                    
                                    2.3%
                                 | |
| 1 | Not effective at all | 19 | 
                                    
                                    6.4%
                                 | 
| 2 | 23 | 
                                    
                                    7.7%
                                 | |
| 3 | 34 | 
                                    
                                    11.4%
                                 | |
| 4 | 23 | 
                                    
                                    7.7%
                                 | |
| 5 | 23 | 
                                    
                                    7.7%
                                 | |
| 6 | 20 | 
                                    
                                    6.7%
                                 | |
| 7 | 21 | 
                                    
                                    7%
                                 | |
| 8 | 6 | 
                                    
                                    2%
                                 | |
| 9 | 8 | 
                                    
                                    2.7%
                                 | |
| 10 | Very effective | 13 | 
                                    
                                    4.4%
                                 | 
| 11 | Don't know | 101 | 
                                    
                                    33.9%
                                 | 
| Sysmiss | 28 |