| Value | Category | Cases | |
|---|---|---|---|
| 1 | 1. Less than 1 year | 0 |
0%
|
| 2 | 2. 1 to 3 years | 15 |
3%
|
| 3 | 3. 4 to 10 years | 108 |
21.5%
|
| 4 | 4. 10 to 20 years | 140 |
27.9%
|
| 5 | 5. Many generations | 239 |
47.6%
|
| Sysmiss | 2445 |