| Value | Category | Cases | |
|---|---|---|---|
| 2000 | 2 |
4%
|
|
| 2008 | 26 |
52%
|
|
| 2009 | 3 |
6%
|
|
| 2010 | 3 |
6%
|
|
| 2011 | 11 |
22%
|
|
| 2012 | 5 |
10%
|
|
| 9998 | don't know | 0 |
0%
|
| Sysmiss | 49136 |