| Value | Category | Cases | |
|---|---|---|---|
| 2008 | 4 |
0.2%
|
|
| 2009 | 9 |
0.5%
|
|
| 2010 | 121 |
7.2%
|
|
| 2011 | 221 |
13.1%
|
|
| 2012 | 659 |
39.1%
|
|
| 2013 | 670 |
39.8%
|
|
| Sysmiss | 18147 |