| Value | Category | Cases | |
|---|---|---|---|
| -2 | don't know | 27 |
48.2%
|
| 7 | 1 |
1.8%
|
|
| 1490 | 1 |
1.8%
|
|
| 1970 | 3 |
5.4%
|
|
| 1980 | 4 |
7.1%
|
|
| 1982 | 1 |
1.8%
|
|
| 1984 | 1 |
1.8%
|
|
| 1985 | 2 |
3.6%
|
|
| 1988 | 2 |
3.6%
|
|
| 1990 | 7 |
12.5%
|
|
| 1992 | 1 |
1.8%
|
|
| 1999 | 1 |
1.8%
|
|
| 2000 | 1 |
1.8%
|
|
| 2006 | 3 |
5.4%
|
|
| 2009 | 1 |
1.8%
|
|
| Sysmiss | 993 |