| Value | Category | Cases | |
|---|---|---|---|
| 1 | Less than 1 year | 11 |
1.4%
|
| 2 | 1 to 2 years | 19 |
2.5%
|
| 3 | Greater than 2 years | 330 |
42.7%
|
| 4 | Undecided | 353 |
45.7%
|
| 98 | Don't know | 60 |
7.8%
|
| Sysmiss | 1416 |