| Value | Category | Cases | |
|---|---|---|---|
| -99 | 14 | 
                                    
                                    4.6%
                                 | |
| 1 | Not effective at all | 14 | 
                                    
                                    4.6%
                                 | 
| 2 | 15 | 
                                    
                                    4.9%
                                 | |
| 3 | 22 | 
                                    
                                    7.2%
                                 | |
| 4 | 27 | 
                                    
                                    8.8%
                                 | |
| 5 | 20 | 
                                    
                                    6.5%
                                 | |
| 6 | 26 | 
                                    
                                    8.5%
                                 | |
| 7 | 11 | 
                                    
                                    3.6%
                                 | |
| 8 | 13 | 
                                    
                                    4.2%
                                 | |
| 9 | 17 | 
                                    
                                    5.5%
                                 | |
| 10 | Very effective | 30 | 
                                    
                                    9.8%
                                 | 
| 11 | Don't know | 98 | 
                                    
                                    31.9%
                                 | 
| Sysmiss | 19 |