| Value | Category | Cases | |
|---|---|---|---|
| 1 | No difficulty | 2667229 | 
                                    
                                    98.7%
                                 | 
| 2 | Yes, some difficulty | 24433 | 
                                    
                                    0.9%
                                 | 
| 3 | Yes, a lot of difficulty | 6500 | 
                                    
                                    0.2%
                                 | 
| 4 | Cannot do at all | 2883 | 
                                    
                                    0.1%
                                 | 
| Sysmiss | 383938 |