| Value | Category | Cases | |
|---|---|---|---|
| 0 | Never | 774 |
90.1%
|
| 1 | Formerly (stopped more than 6 months ago) | 30 |
3.5%
|
| 2 | Current (in last 6 months) | 55 |
6.4%
|
| Sysmiss | 6 |