| Value | Category | Cases | |
|---|---|---|---|
| 0 | 471 |
98.5%
|
|
| 1998 | 1 |
0.2%
|
|
| 2008 | 1 |
0.2%
|
|
| 2009 | 1 |
0.2%
|
|
| 2010 | 4 |
0.8%
|
|
| Sysmiss | 2 |