| Value | Category | Cases | |
|---|---|---|---|
| 1 | 1 year or less | 493 |
22.3%
|
| 2 | Between 1 and 2 years | 265 |
12%
|
| 3 | More than 2 years | 650 |
29.3%
|
| 4 | Never | 787 |
35.5%
|
| 77 | Don't know | 20 |
0.9%
|
| Sysmiss | 1837 |