| Value | Category | Cases | |
|---|---|---|---|
| 0 | 306 |
64%
|
|
| 1999 | 2 |
0.4%
|
|
| 2000 | 2 |
0.4%
|
|
| 2001 | 1 |
0.2%
|
|
| 2002 | 3 |
0.6%
|
|
| 2004 | 2 |
0.4%
|
|
| 2005 | 10 |
2.1%
|
|
| 2006 | 20 |
4.2%
|
|
| 2007 | 37 |
7.7%
|
|
| 2008 | 54 |
11.3%
|
|
| 2009 | 24 |
5%
|
|
| 2010 | 16 |
3.3%
|
|
| 2011 | 1 |
0.2%
|
|
| Sysmiss | 2 |