| Value | Category | Cases | |
|---|---|---|---|
| 1996 | 2 |
1.1%
|
|
| 1998 | 5 |
2.8%
|
|
| 1999 | 6 |
3.4%
|
|
| 2000 | 12 |
6.7%
|
|
| 2001 | 1 |
0.6%
|
|
| 2002 | 3 |
1.7%
|
|
| 2003 | 7 |
3.9%
|
|
| 2004 | 13 |
7.3%
|
|
| 2005 | 9 |
5.1%
|
|
| 2006 | 14 |
7.9%
|
|
| 2007 | 6 |
3.4%
|
|
| 2008 | 6 |
3.4%
|
|
| 2009 | 8 |
4.5%
|
|
| 2010 | 3 |
1.7%
|
|
| 2011 | 6 |
3.4%
|
|
| 2013 | 7 |
3.9%
|
|
| 2014 | 9 |
5.1%
|
|
| 2015 | 1 |
0.6%
|
|
| Missing value | 60 |
33.7%
|