| Value | Category | Cases | |
|---|---|---|---|
| 1 | Less than 1 year | 44 |
2.9%
|
| 2 | 1 to 3 years | 175 |
11.5%
|
| 3 | 4 to 10 years | 525 |
34.5%
|
| 4 | 10 to 20 years | 482 |
31.6%
|
| 5 | Many generations | 297 |
19.5%
|
| Sysmiss | 3794 |