| Value | Category | Cases | |
|---|---|---|---|
| 2007 | 1 |
0.2%
|
|
| 2008 | 44 |
9.1%
|
|
| 2009 | 105 |
21.8%
|
|
| 2010 | 117 |
24.3%
|
|
| 2011 | 126 |
26.2%
|
|
| 2012 | 86 |
17.9%
|
|
| 9999 | Missing | 2 |
0.4%
|
| Sysmiss | 2649 |