| Value | Category | Cases | |
|---|---|---|---|
| -99 | Don't know | 36 |
52.2%
|
| 1975 | 1 |
1.4%
|
|
| 1986 | 1 |
1.4%
|
|
| 1990 | 2 |
2.9%
|
|
| 1992 | 1 |
1.4%
|
|
| 1993 | 2 |
2.9%
|
|
| 1994 | 2 |
2.9%
|
|
| 1995 | 2 |
2.9%
|
|
| 1996 | 2 |
2.9%
|
|
| 1999 | 1 |
1.4%
|
|
| 2000 | 5 |
7.2%
|
|
| 2001 | 6 |
8.7%
|
|
| 2003 | 1 |
1.4%
|
|
| 2004 | 1 |
1.4%
|
|
| 2007 | 3 |
4.3%
|
|
| 2009 | 3 |
4.3%
|
|
| Sysmiss | 117 |