| Value | Category | Cases | |
|---|---|---|---|
| 0 | Never | 826 |
96.2%
|
| 1 | Formerly (stopped more than 6 months ago) | 11 |
1.3%
|
| 2 | Current (in last 6 months) | 22 |
2.6%
|
| Sysmiss | 6 |