| Value | Category | Cases | |
|---|---|---|---|
| 1 | From 9 months to 5 years | 0 |
0%
|
| 2 | Every 6 months | 24 |
100%
|
| 88 | Other (specify:) | 0 |
0%
|
| 98 | Don?t know | 0 |
0%
|
| Sysmiss | 164 |