| Value | Category | Cases | |
|---|---|---|---|
| 1 | No difficulty | 2603835 |
96.4%
|
| 2 | Yes, some difficulty | 72295 |
2.7%
|
| 3 | Yes, a lot of difficulty | 21515 |
0.8%
|
| 4 | Cannot do at all | 3400 |
0.1%
|
| Sysmiss | 383938 |