| Value | Category | Cases | |
|---|---|---|---|
| 2008 | 487 |
3.6%
|
|
| 2009 | 556 |
4.1%
|
|
| 2010 | 11 |
0.1%
|
|
| 9999 | Missing | 5 |
0%
|
| Sysmiss | 12528 |
92.2%
|