| Value | Category | Cases | |
|---|---|---|---|
| 1 | Not effective at all | 3 | 
                                    
                                    0.5%
                                 | 
| 2 | 18 | 
                                    
                                    3%
                                 | |
| 3 | 29 | 
                                    
                                    4.8%
                                 | |
| 4 | 42 | 
                                    
                                    6.9%
                                 | |
| 5 | 63 | 
                                    
                                    10.3%
                                 | |
| 6 | 79 | 
                                    
                                    13%
                                 | |
| 7 | 90 | 
                                    
                                    14.8%
                                 | |
| 8 | 64 | 
                                    
                                    10.5%
                                 | |
| 9 | 43 | 
                                    
                                    7%
                                 | |
| 10 | Very effective | 36 | 
                                    
                                    5.9%
                                 | 
| 11 | Don't know | 143 | 
                                    
                                    23.4%
                                 | 
| Sysmiss | 14 |