| Value | Category | Cases | |
|---|---|---|---|
| -999 | -999 | 0 |
0%
|
| -888 | -888 | 24 |
15%
|
| 1 | More than one month | 15 |
9.4%
|
| 2 | Once every month | 10 |
6.3%
|
| 3 | Once every two months | 14 |
8.8%
|
| 4 | Once every three months | 53 |
33.1%
|
| 5 | Less than once every three months | 44 |
27.5%
|
| Sysmiss | 752 |