| Value | Category | Cases | |
|---|---|---|---|
| 1 | Once a year | 264 |
1.6%
|
| 2 | Every six months | 6191 |
38.1%
|
| 3 | More often than once every 6 months | 3105 |
19.1%
|
| 5 | Deprecated (in IQ1/3, not IQ2) | 5436 |
33.5%
|
| 6 | Don't know | 498 |
3.1%
|
| 7 | Not applicable | 704 |
4.3%
|
| 8 | Refused | 0 |
0%
|
| 9 | Missing | 51 |
0.3%
|