| Value | Category | Cases | |
|---|---|---|---|
| 2008 | 3 |
10.7%
|
|
| 2009 | 4 |
14.3%
|
|
| 2010 | 10 |
35.7%
|
|
| 2011 | 11 |
39.3%
|
|
| 9999 | Missing | 0 |
0%
|
| Sysmiss | 2304 |