| Value | Category | Cases | |
|---|---|---|---|
| 1 | Once in 2 weeks | 40 |
9.3%
|
| 2 | Once a month | 353 |
82.3%
|
| 3 | Once in 3 months | 20 |
4.7%
|
| 4 | Once in 6 months | 16 |
3.7%
|
| Sysmiss | 84 |