| Value | Category | Cases | |
|---|---|---|---|
| -99 | Don't know | 41 |
55.4%
|
| 1985 | 2 |
2.7%
|
|
| 1990 | 1 |
1.4%
|
|
| 1995 | 2 |
2.7%
|
|
| 1996 | 3 |
4.1%
|
|
| 1999 | 4 |
5.4%
|
|
| 2000 | 1 |
1.4%
|
|
| 2002 | 1 |
1.4%
|
|
| 2003 | 1 |
1.4%
|
|
| 2004 | 3 |
4.1%
|
|
| 2005 | 4 |
5.4%
|
|
| 2006 | 3 |
4.1%
|
|
| 2007 | 3 |
4.1%
|
|
| 2008 | 1 |
1.4%
|
|
| 2009 | 4 |
5.4%
|
|
| Sysmiss | 112 |