| Value | Category | Cases | |
|---|---|---|---|
| 2007 | 22 |
9.5%
|
|
| 2008 | 44 |
19%
|
|
| 2009 | 40 |
17.2%
|
|
| 2010 | 69 |
29.7%
|
|
| 2011 | 57 |
24.6%
|
|
| 9999 | Missing | 0 |
0%
|
| Sysmiss | 396 |