| Value | Category | Cases | |
|---|---|---|---|
| 1 | 1 hour | 240 |
8.1%
|
| 2 | 2 hours | 723 |
24.4%
|
| 3 | 3 hours | 1321 |
44.6%
|
| 4 | 4 hours or more | 679 |
22.9%
|
| Sysmiss | 364 |