| Value | Category | Cases | |
|---|---|---|---|
| 1 | before 1945 | 140 |
7.9%
|
| 2 | 1945-1960 | 212 |
11.9%
|
| 3 | 1961-1980 | 590 |
33.1%
|
| 4 | 1981-1990 | 423 |
23.8%
|
| 5 | after 1990 | 415 |
23.3%
|
| Sysmiss | 2 |