| Value | Category | Cases | |
|---|---|---|---|
| -99 | Don't know | 43 |
55.8%
|
| 1990 | 1 |
1.3%
|
|
| 1994 | 1 |
1.3%
|
|
| 1996 | 1 |
1.3%
|
|
| 1997 | 1 |
1.3%
|
|
| 2000 | 1 |
1.3%
|
|
| 2001 | 2 |
2.6%
|
|
| 2002 | 1 |
1.3%
|
|
| 2003 | 4 |
5.2%
|
|
| 2004 | 8 |
10.4%
|
|
| 2005 | 10 |
13%
|
|
| 2006 | 1 |
1.3%
|
|
| 2007 | 2 |
2.6%
|
|
| 2008 | 1 |
1.3%
|
|
| Sysmiss | 109 |