| Value | Category | Cases | |
|---|---|---|---|
| 10 | 1 |
0.1%
|
|
| 11 | 2 |
0.3%
|
|
| 999 | 1 |
0.1%
|
|
| 2008 | 3 |
0.4%
|
|
| 2009 | 19 |
2.6%
|
|
| 2010 | 453 |
62.9%
|
|
| 2011 | 235 |
32.6%
|
|
| 9999 | 6 |
0.8%
|
|
| Sysmiss | 230 |