| Value | Category | Cases | |
|---|---|---|---|
| 1 | NO DIFFICULTY | 1 |
0.1%
|
| 2 | SOME DIFFICULTY | 3 |
0.2%
|
| 4 | CANNOT WALK 500 M AT ALL | 1 |
0.1%
|
| Sysmiss | 1819 |
99.7%
|