| Value | Category | Cases | |
|---|---|---|---|
| -9 | don't know | 66 |
13.3%
|
| -8 | does not apply | 0 |
0%
|
| -7 | refused to answer | 0 |
0%
|
| 1995 | 1 |
0.2%
|
|
| 1997 | 1 |
0.2%
|
|
| 1998 | 2 |
0.4%
|
|
| 2000 | 2 |
0.4%
|
|
| 2001 | 12 |
2.4%
|
|
| 2002 | 14 |
2.8%
|
|
| 2003 | 37 |
7.4%
|
|
| 2004 | 33 |
6.6%
|
|
| 2005 | 110 |
22.1%
|
|
| 2006 | 137 |
27.5%
|
|
| 2007 | 76 |
15.3%
|
|
| 2008 | 7 |
1.4%
|
|
| Sysmiss | 258 |