| Value | Category | Cases | |
|---|---|---|---|
| 1 | 1. dark gloomy | 115 |
2.6%
|
| 2 | 2. poor light | 443 |
10.2%
|
| 3 | 3. average light | 1285 |
29.5%
|
| 4 | 4. bright | 2422 |
55.5%
|
| 77 | 77. d/r | 0 |
0%
|
| 99 | 99. missing | 96 |
2.2%
|
| Sysmiss | 177 |