| Value | Category | Cases | |
|---|---|---|---|
| 1 | No, no difficulty at all | 20478 |
98.9%
|
| 2 | Yes, some difficulty | 169 |
0.8%
|
| 3 | Yes, a lot of difficulty | 38 |
0.2%
|
| 4 | Cannot see at all | 15 |
0.1%
|
| 5 | Do not know | 3 |
0%
|