| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 2 |
7.1%
|
| 1 | One hour or less | 1 |
3.6%
|
| 2 | 3 |
10.7%
|
|
| 4 | 5 |
17.9%
|
|
| 6 | 2 |
7.1%
|
|
| 8 | 5 |
17.9%
|
|
| 12 | 1 |
3.6%
|
|
| 16 | 1 |
3.6%
|
|
| 24 | 4 |
14.3%
|
|
| 36 | 3 |
10.7%
|
|
| 60 | 1 |
3.6%
|
|
| Sysmiss | 584 |