| Value | Category | Cases | |
|---|---|---|---|
| 1 | 1 year or less | 95 |
15.1%
|
| 2 | Between 1 and 2 years | 62 |
9.9%
|
| 3 | More than 2 years | 53 |
8.4%
|
| 4 | Never | 396 |
63.1%
|
| 77 | Don't know | 22 |
3.5%
|
| Sysmiss | 4810 |