| Value | Category | Cases | |
|---|---|---|---|
| 1 | 1 yr or less | 478 |
22.4%
|
| 2 | between 1 and 2 yrs | 121 |
5.7%
|
| 3 | more than 2 yrs | 598 |
28.1%
|
| 4 | never | 884 |
41.5%
|
| 77 | don't know | 50 |
2.3%
|
| Sysmiss | 1677 |