| Value | Category | Cases | |
|---|---|---|---|
| 1 | a. Once per month or more often | 1901 |
67%
|
| 2 | b. Once per every two months | 860 |
30.3%
|
| 3 | c. Once per every six months or year | 76 |
2.7%
|
| Sysmiss | 1669 |