| Value | Category | Cases | |
|---|---|---|---|
| 1 | 1 yr or less | 475 |
29.1%
|
| 2 | between 1 and 2 yrs | 286 |
17.5%
|
| 3 | more than 2 yrs | 378 |
23.1%
|
| 4 | never | 485 |
29.7%
|
| 77 | don't know | 9 |
0.6%
|
| Sysmiss | 1103 |