| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 14 |
25%
|
| 1970 | 2 |
3.6%
|
|
| 1984 | 1 |
1.8%
|
|
| 1985 | 1 |
1.8%
|
|
| 1988 | 1 |
1.8%
|
|
| 1989 | 1 |
1.8%
|
|
| 1992 | 1 |
1.8%
|
|
| 1995 | 1 |
1.8%
|
|
| 1996 | 1 |
1.8%
|
|
| 1997 | 2 |
3.6%
|
|
| 1998 | 1 |
1.8%
|
|
| 1999 | 1 |
1.8%
|
|
| 2000 | 3 |
5.4%
|
|
| 2002 | 1 |
1.8%
|
|
| 2005 | 2 |
3.6%
|
|
| 2007 | 1 |
1.8%
|
|
| 2008 | 1 |
1.8%
|
|
| 2011 | 1 |
1.8%
|
|
| 2012 | 1 |
1.8%
|
|
| 2014 | 5 |
8.9%
|
|
| 2015 | 4 |
7.1%
|
|
| 2016 | 1 |
1.8%
|
|
| 2018 | 2 |
3.6%
|
|
| 2019 | 1 |
1.8%
|
|
| 2020 | 2 |
3.6%
|
|
| 2021 | 1 |
1.8%
|
|
| 2022 | 2 |
3.6%
|
|
| 2023 | 1 |
1.8%
|
|
| Sysmiss | 94 |