| Value | Category | Cases | |
|---|---|---|---|
| 1 | Less than 1 year | 4 |
0.4%
|
| 2 | 1 to 3 years | 92 |
9.7%
|
| 3 | 4 to 10 years | 231 |
24.4%
|
| 4 | 10 to 20 years | 341 |
36%
|
| 5 | Many generations | 280 |
29.5%
|
| Sysmiss | 4369 |