| Value | Category | Cases | |
|---|---|---|---|
| 1 | Less than 2 years | 29 |
1.2%
|
| 2 | 2 to 5 years | 279 |
11.2%
|
| 3 | 6 to 10 years | 516 |
20.6%
|
| 4 | More than 10 years | 1666 |
66.6%
|
| 98 | Don’t know | 12 |
0.5%
|
| Sysmiss | 271 |