| Value | Category | Cases | |
|---|---|---|---|
| 2007 | 9 |
9%
|
|
| 2008 | 20 |
20%
|
|
| 2009 | 15 |
15%
|
|
| 2010 | 28 |
28%
|
|
| 2011 | 28 |
28%
|
|
| 9999 | Missing | 0 |
0%
|
| Sysmiss | 660 |