| Value | Category | Cases | |
|---|---|---|---|
| 1 | None | 187 |
27.1%
|
| 2 | Less than 6 hours | 174 |
25.3%
|
| 3 | 6–15 hours | 162 |
23.5%
|
| 4 | 16–35 hours | 90 |
13.1%
|
| 5 | More than 35 hours | 76 |
11%
|
| Sysmiss | 311 |