| Value | Category | Cases | |
|---|---|---|---|
| 0 | None | 4 |
6.7%
|
| 1 | < 4 hours per night | 25 |
41.7%
|
| 2 | > 4 hours per night | 23 |
38.3%
|
| 9 | Unknown | 8 |
13.3%
|