| Value | Category | Cases | |
|---|---|---|---|
| 0 | took the test every 2 or 3 years | 0 |
0%
|
| 1 | only once | 22 |
88%
|
| 2 | every year | 0 |
0%
|
| 3 | every 6 months | 0 |
0%
|
| 4 | every 3 months | 1 |
4%
|
| 5 | took the test more than 3 times | 1 |
4%
|
| 6 | other | 0 |
0%
|
| 7 | took the test 2 times | 0 |
0%
|
| 8 | took the test 3 times | 1 |
4%
|
| Sysmiss | 105 |