| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 1 |
1.1%
|
| 1 | One month or less | 22 |
23.4%
|
| 2 | 27 |
28.7%
|
|
| 3 | 26 |
27.7%
|
|
| 4 | 9 |
9.6%
|
|
| 6 | 9 |
9.6%
|
|
| Sysmiss | 504 |