| Value | Category | Cases | |
|---|---|---|---|
| -99 | 10 | 
                                    
                                    3.4%
                                 | |
| 1 | Not effective at all | 13 | 
                                    
                                    4.5%
                                 | 
| 2 | 19 | 
                                    
                                    6.5%
                                 | |
| 3 | 22 | 
                                    
                                    7.5%
                                 | |
| 4 | 22 | 
                                    
                                    7.5%
                                 | |
| 5 | 25 | 
                                    
                                    8.6%
                                 | |
| 6 | 21 | 
                                    
                                    7.2%
                                 | |
| 7 | 25 | 
                                    
                                    8.6%
                                 | |
| 8 | 8 | 
                                    
                                    2.7%
                                 | |
| 9 | 9 | 
                                    
                                    3.1%
                                 | |
| 10 | Very effective | 21 | 
                                    
                                    7.2%
                                 | 
| 11 | Don't know | 97 | 
                                    
                                    33.2%
                                 | 
| Sysmiss | 34 |