| Value | Category | Cases | |
|---|---|---|---|
| 2007 | 2 |
4.8%
|
|
| 2008 | 4 |
9.5%
|
|
| 2009 | 6 |
14.3%
|
|
| 2010 | 15 |
35.7%
|
|
| 2011 | 13 |
31%
|
|
| 2012 | 2 |
4.8%
|
|
| 9999 | Missing | 0 |
0%
|
| Sysmiss | 718 |