| Value | Category | Cases | |
|---|---|---|---|
| 2008 | 255 |
1.9%
|
|
| 2009 | 642 |
4.7%
|
|
| 2010 | 21 |
0.2%
|
|
| 9999 | Missing | 7 |
0.1%
|
| Sysmiss | 12662 |
93.2%
|