| Value | Category | Cases | |
|---|---|---|---|
| 2001 | 1 |
0.1%
|
|
| 2007 | 1 |
0.1%
|
|
| 2008 | 2 |
0.1%
|
|
| 2009 | 1423 |
93.1%
|
|
| 2010 | 78 |
5.1%
|
|
| 7777 | DON'T KNOW | 23 |
1.5%
|
| Sysmiss | 6630 |