| Value | Category | Cases | |
|---|---|---|---|
| -95 | 2 | 
                                    
                                    1%
                                 | |
| 1 | Very difficult | 2 | 
                                    
                                    1%
                                 | 
| 2 | Difficult | 19 | 
                                    
                                    9%
                                 | 
| 3 | Somewhat difficult | 29 | 
                                    
                                    13.8%
                                 | 
| 4 | Easy | 137 | 
                                    
                                    65.2%
                                 | 
| 5 | Very easy | 21 | 
                                    
                                    10%
                                 |