| Value | Category | Cases | |
|---|---|---|---|
| -99 | 3 | 
                                    
                                    1%
                                 | |
| 1 | Not effective at all | 18 | 
                                    
                                    6.2%
                                 | 
| 2 | 20 | 
                                    
                                    6.8%
                                 | |
| 3 | 16 | 
                                    
                                    5.5%
                                 | |
| 4 | 15 | 
                                    
                                    5.1%
                                 | |
| 5 | 29 | 
                                    
                                    9.9%
                                 | |
| 6 | 16 | 
                                    
                                    5.5%
                                 | |
| 7 | 14 | 
                                    
                                    4.8%
                                 | |
| 8 | 8 | 
                                    
                                    2.7%
                                 | |
| 9 | 4 | 
                                    
                                    1.4%
                                 | |
| 10 | Very effective | 3 | 
                                    
                                    1%
                                 | 
| 11 | Don't know | 146 | 
                                    
                                    50%
                                 | 
| Sysmiss | 9 |