| Value | Category | Cases | |
|---|---|---|---|
| 1977 | 2 |
0.8%
|
|
| 1994 | 2 |
0.8%
|
|
| 1996 | 4 |
1.5%
|
|
| 1998 | 1 |
0.4%
|
|
| 2000 | 1 |
0.4%
|
|
| 2001 | 2 |
0.8%
|
|
| 2002 | 1 |
0.4%
|
|
| 2003 | 2 |
0.8%
|
|
| 2005 | 3 |
1.2%
|
|
| 2006 | 6 |
2.3%
|
|
| 2007 | 8 |
3.1%
|
|
| 2008 | 10 |
3.8%
|
|
| 2009 | 16 |
6.2%
|
|
| 2010 | 10 |
3.8%
|
|
| 2011 | 20 |
7.7%
|
|
| 2012 | 11 |
4.2%
|
|
| 2013 | 29 |
11.2%
|
|
| 2014 | 32 |
12.3%
|
|
| 2015 | 7 |
2.7%
|
|
| 2016 | 24 |
9.2%
|
|
| 2017 | 37 |
14.2%
|
|
| 2018 | 21 |
8.1%
|
|
| 2019 | 10 |
3.8%
|
|
| Missing value | 1 |
0.4%
|