| Value | Category | Cases | |
|---|---|---|---|
| -9 | don't know | 40 |
7.5%
|
| -8 | does not apply | 0 |
0%
|
| -7 | refused to answer | 0 |
0%
|
| 1996 | 1 |
0.2%
|
|
| 1998 | 1 |
0.2%
|
|
| 1999 | 1 |
0.2%
|
|
| 2000 | 3 |
0.6%
|
|
| 2001 | 6 |
1.1%
|
|
| 2002 | 4 |
0.7%
|
|
| 2003 | 8 |
1.5%
|
|
| 2004 | 21 |
3.9%
|
|
| 2005 | 70 |
13.1%
|
|
| 2006 | 155 |
28.9%
|
|
| 2007 | 138 |
25.7%
|
|
| 2008 | 87 |
16.2%
|
|
| 2009 | 1 |
0.2%
|
|
| Sysmiss | 220 |