| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 1 |
2.5%
|
| 0 | Less than 1 hour | 4 |
10%
|
| 1 | 5 |
12.5%
|
|
| 2 | 6 |
15%
|
|
| 3 | 5 |
12.5%
|
|
| 4 | 7 |
17.5%
|
|
| 5 | 7 |
17.5%
|
|
| 6 | 1 |
2.5%
|
|
| 9 | 1 |
2.5%
|
|
| 15 | 1 |
2.5%
|
|
| 24 | 1 |
2.5%
|
|
| 720 | 1 |
2.5%
|
|
| Sysmiss | 352 |