| Value | Category | Cases | |
|---|---|---|---|
| 1 | 4 or less hours | 449 |
23.1%
|
| 2 | 5 hours | 285 |
14.7%
|
| 3 | 6 hours | 247 |
12.7%
|
| 4 | 7 hours | 198 |
10.2%
|
| 5 | 8 hours | 348 |
17.9%
|
| 6 | 9 hours | 167 |
8.6%
|
| 7 | 10 hours | 138 |
7.1%
|
| 8 | 11 or more hours | 109 |
5.6%
|
| Sysmiss | 54 |