| Value | Category | Cases | |
|---|---|---|---|
| 1 | Less tha | 0 |
0%
|
| 2 | A month | 2 |
3.9%
|
| 3 | 6 to 12 | 1 |
2%
|
| 4 | over 12 | 48 |
94.1%
|
| Sysmiss | 9 |