| Value | Category | Cases | |
|---|---|---|---|
| -99 | 7 | 
                                    
                                    2.3%
                                 | |
| 1 | Not effective at all | 12 | 
                                    
                                    4%
                                 | 
| 2 | 17 | 
                                    
                                    5.7%
                                 | |
| 3 | 11 | 
                                    
                                    3.7%
                                 | |
| 4 | 21 | 
                                    
                                    7%
                                 | |
| 5 | 22 | 
                                    
                                    7.4%
                                 | |
| 6 | 18 | 
                                    
                                    6%
                                 | |
| 7 | 21 | 
                                    
                                    7%
                                 | |
| 8 | 19 | 
                                    
                                    6.4%
                                 | |
| 9 | 9 | 
                                    
                                    3%
                                 | |
| 10 | Very effective | 31 | 
                                    
                                    10.4%
                                 | 
| 11 | Don't know | 111 | 
                                    
                                    37.1%
                                 | 
| Sysmiss | 27 |