| Value | Category | Cases | |
|---|---|---|---|
| 1954 | 1 |
14.3%
|
|
| 1956 | 2 |
28.6%
|
|
| 1963 | 1 |
14.3%
|
|
| 1971 | 1 |
14.3%
|
|
| 1981 | 1 |
14.3%
|
|
| 1987 | 1 |
14.3%
|
|
| 9999 | 9999. Don't know | 0 |
0%
|
| Sysmiss | 992 |