| Value | Category | Cases | |
|---|---|---|---|
| 0 | never | 0 |
0%
|
| 1 | every 3 months | 993 |
8%
|
| 2 | every 6 months | 2004 |
16.1%
|
| 3 | every year | 6635 |
53.4%
|
| 4 | every 5 years | 476 |
3.8%
|
| 5 | never | 1039 |
8.4%
|
| 6 | other | 795 |
6.4%
|
| 8 | don't know | 473 |
3.8%
|
| Sysmiss | 500 |