| Value | Category | Cases | |
|---|---|---|---|
| 2007 | 5 |
6.8%
|
|
| 2008 | 23 |
31.1%
|
|
| 2009 | 21 |
28.4%
|
|
| 2010 | 19 |
25.7%
|
|
| 2011 | 6 |
8.1%
|
|
| 9999 | Missing | 0 |
0%
|
| Sysmiss | 1848 |