| Value | Category | Cases | |
|---|---|---|---|
| -998 | don't know | 0 |
0%
|
| 0 | Never | 1 |
33.3%
|
| 1 | 1 |
33.3%
|
|
| 2 | 1 |
33.3%
|
|
| 13 | More than one year | 0 |
0%
|
| Sysmiss | 2243 |