| Value | Category | Cases | |
|---|---|---|---|
| 2008 | 255 |
27.6%
|
|
| 2009 | 642 |
69.4%
|
|
| 2010 | 21 |
2.3%
|
|
| 9999 | Missing | 7 |
0.8%
|
| Sysmiss | 12662 |