| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| 1975 | 1 |
1.9%
|
|
| 1976 | 1 |
1.9%
|
|
| 1979 | 1 |
1.9%
|
|
| 1993 | 1 |
1.9%
|
|
| 1998 | 1 |
1.9%
|
|
| 1999 | 1 |
1.9%
|
|
| 2000 | 1 |
1.9%
|
|
| 2002 | 1 |
1.9%
|
|
| 2006 | 1 |
1.9%
|
|
| 2007 | 2 |
3.8%
|
|
| 2008 | 1 |
1.9%
|
|
| 2009 | 1 |
1.9%
|
|
| 2010 | 3 |
5.7%
|
|
| 2011 | 1 |
1.9%
|
|
| 2013 | 3 |
5.7%
|
|
| 2014 | 5 |
9.4%
|
|
| 2015 | 5 |
9.4%
|
|
| 2016 | 2 |
3.8%
|
|
| 2017 | 3 |
5.7%
|
|
| 2019 | 3 |
5.7%
|
|
| 2020 | 7 |
13.2%
|
|
| 2021 | 3 |
5.7%
|
|
| 2022 | 4 |
7.5%
|
|
| 2023 | 1 |
1.9%
|
|
| Sysmiss | 305 |