| Value | Category | Cases | |
|---|---|---|---|
| 0 | never | 0 |
0%
|
| 1 | every 3 months | 4076 |
11.8%
|
| 2 | every 6 months | 6117 |
17.7%
|
| 3 | every year | 14816 |
42.8%
|
| 4 | every 5 years | 1499 |
4.3%
|
| 5 | never | 3581 |
10.4%
|
| 6 | other | 4500 |
13%
|
| Sysmiss | 1194 |