| 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 |