| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 5 |
3%
|
| 1951 | 1 |
0.6%
|
|
| 1989 | 1 |
0.6%
|
|
| 1991 | 1 |
0.6%
|
|
| 1996 | 1 |
0.6%
|
|
| 1999 | 3 |
1.8%
|
|
| 2000 | 3 |
1.8%
|
|
| 2001 | 1 |
0.6%
|
|
| 2002 | 2 |
1.2%
|
|
| 2004 | 2 |
1.2%
|
|
| 2005 | 3 |
1.8%
|
|
| 2006 | 2 |
1.2%
|
|
| 2007 | 5 |
3%
|
|
| 2008 | 6 |
3.6%
|
|
| 2009 | 5 |
3%
|
|
| 2010 | 6 |
3.6%
|
|
| 2011 | 5 |
3%
|
|
| 2012 | 7 |
4.2%
|
|
| 2013 | 7 |
4.2%
|
|
| 2014 | 8 |
4.8%
|
|
| 2015 | 15 |
9%
|
|
| 2016 | 16 |
9.6%
|
|
| 2017 | 10 |
6%
|
|
| 2018 | 12 |
7.2%
|
|
| 2019 | 8 |
4.8%
|
|
| 2020 | 14 |
8.4%
|
|
| 2021 | 4 |
2.4%
|
|
| 2022 | 10 |
6%
|
|
| 2023 | 4 |
2.4%
|
|
| Sysmiss | 846 |