| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 29 |
46.8%
|
| 1965 | 1 |
1.6%
|
|
| 1970 | 1 |
1.6%
|
|
| 1978 | 1 |
1.6%
|
|
| 1990 | 1 |
1.6%
|
|
| 1994 | 1 |
1.6%
|
|
| 2000 | 1 |
1.6%
|
|
| 2001 | 1 |
1.6%
|
|
| 2002 | 2 |
3.2%
|
|
| 2005 | 2 |
3.2%
|
|
| 2006 | 1 |
1.6%
|
|
| 2007 | 1 |
1.6%
|
|
| 2008 | 1 |
1.6%
|
|
| 2009 | 1 |
1.6%
|
|
| 2015 | 2 |
3.2%
|
|
| 2016 | 5 |
8.1%
|
|
| 2017 | 5 |
8.1%
|
|
| 2018 | 4 |
6.5%
|
|
| 2019 | 2 |
3.2%
|
|
| Sysmiss | 87 |