| Value | Category | Cases | |
|---|---|---|---|
| 2008 | 1 |
3.2%
|
|
| 2009 | 10 |
32.3%
|
|
| 2010 | 13 |
41.9%
|
|
| 2011 | 7 |
22.6%
|
|
| 9999 | Missing | 0 |
0%
|
| Sysmiss | 729 |