| Value | Category | Cases | |
|---|---|---|---|
| 1 | Two years or less | 2341 |
25.5%
|
| 2 | Three to five years | 1935 |
21.1%
|
| 3 | More than five years | 4552 |
49.5%
|
| 4 | Don't know | 362 |
3.9%
|
| Sysmiss | 4125 |