| Value | Category | Cases | |
|---|---|---|---|
| 1997 | 1 |
0.1%
|
|
| 2001 | 2 |
0.2%
|
|
| 2002 | 1 |
0.1%
|
|
| 2005 | 1 |
0.1%
|
|
| 2006 | 3 |
0.4%
|
|
| 2007 | 1 |
0.1%
|
|
| 2008 | 1 |
0.1%
|
|
| 2009 | 5 |
0.6%
|
|
| 2010 | 4 |
0.5%
|
|
| 2011 | 44 |
5.2%
|
|
| 2012 | 145 |
17.1%
|
|
| 2013 | 281 |
33.1%
|
|
| 2014 | 90 |
10.6%
|
|
| 2015 | 9 |
1.1%
|
|
| 2016 | 10 |
1.2%
|
|
| 2018 | 4 |
0.5%
|
|
| Missing value | 247 |
29.1%
|