| Value | Category | Cases | |
|---|---|---|---|
| 0 | 3 |
1.9%
|
|
| 1997 | 1 |
0.6%
|
|
| 1998 | 1 |
0.6%
|
|
| 2000 | 3 |
1.9%
|
|
| 2001 | 3 |
1.9%
|
|
| 2002 | 2 |
1.3%
|
|
| 2003 | 5 |
3.1%
|
|
| 2004 | 6 |
3.8%
|
|
| 2005 | 9 |
5.7%
|
|
| 2006 | 12 |
7.5%
|
|
| 2007 | 10 |
6.3%
|
|
| 2008 | 18 |
11.3%
|
|
| 2009 | 10 |
6.3%
|
|
| 2010 | 11 |
6.9%
|
|
| 2011 | 13 |
8.2%
|
|
| 2012 | 14 |
8.8%
|
|
| 2013 | 38 |
23.9%
|
|
| Sysmiss | 741 |