| Value | Category | Cases | |
|---|---|---|---|
| 1 | Less than a year | 749 |
33.8%
|
| 2 | 1 year to less than 3 years | 1087 |
49.1%
|
| 3 | 3 years or more | 360 |
16.3%
|
| 9 | Unspecified | 18 |
0.8%
|
| Sysmiss | 64215 |