| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 3 |
3%
|
| 0 | Less than 1 hour | 34 |
34%
|
| 1 | 19 |
19%
|
|
| 2 | 17 |
17%
|
|
| 3 | 3 |
3%
|
|
| 4 | 7 |
7%
|
|
| 5 | 4 |
4%
|
|
| 6 | 2 |
2%
|
|
| 7 | 1 |
1%
|
|
| 8 | 2 |
2%
|
|
| 10 | 1 |
1%
|
|
| 12 | 1 |
1%
|
|
| 13 | 1 |
1%
|
|
| 24 | 2 |
2%
|
|
| 30 | 1 |
1%
|
|
| 40 | 1 |
1%
|
|
| 50 | 1 |
1%
|
|
| Sysmiss | 1418 |