| Value | Category | Cases | |
|---|---|---|---|
| 1 | Once a quarter | 2227 |
23.9%
|
| 2 | Once a year | 3472 |
37.3%
|
| 3 | Once a 2 year period | 53 |
0.6%
|
| 4 | None | 553 |
5.9%
|
| 5 | When sick | 3009 |
32.3%
|
| Sysmiss | 68 |