| Value | Category | Cases | |
|---|---|---|---|
| 1 | no difficulty remembering/concentrating | 3991 |
98.3%
|
| 2 | some difficulty | 39 |
1%
|
| 3 | a lot of difficulty | 14 |
0.3%
|
| 4 | cannot remember/concentrate at all | 13 |
0.3%
|
| 8 | don't know | 1 |
0%
|
| Sysmiss | 8891 |