| Value | Category | Cases | |
|---|---|---|---|
| -999 | -999 | 3 |
0.3%
|
| -888 | -888 | 19 |
1.8%
|
| 1 | Monthly | 190 |
18.2%
|
| 2 | Every 3 months | 22 |
2.1%
|
| 3 | Every 6 month | 104 |
10%
|
| 4 | Annually | 704 |
67.6%
|
| Sysmiss | 3908 |