| Value | Category | Cases | |
|---|---|---|---|
| 1 | No, no difficulty at all | 18497 |
89.3%
|
| 2 | Yes, some difficulty | 1924 |
9.3%
|
| 3 | Yes, a lot of difficulty | 251 |
1.2%
|
| 4 | Cannot see at all | 29 |
0.1%
|
| 5 | Do not know | 2 |
0%
|