| Value | Category | Cases | |
|---|---|---|---|
| 0 | easy | 38 | 
                                    
                                    0.8%
                                 | 
| 1 | moderate | 56 | 
                                    
                                    1.1%
                                 | 
| 2 | difficult | 289 | 
                                    
                                    5.9%
                                 | 
| 3 | not applicable | 4538 | 
                                    
                                    92.2%
                                 | 
| Sysmiss | 37 |