| Value | Category | Cases | |
|---|---|---|---|
| 1 | No difficulty | 32225 |
90.5%
|
| 2 | Some difficulty | 2977 |
8.4%
|
| 3 | A lot of difficulty | 252 |
0.7%
|
| 4 | Cannot concentrate at all | 126 |
0.4%
|
| 9 | No response | 17 |
0%
|
| Sysmiss | 1455 |