| Value | Category | Cases | |
|---|---|---|---|
| 2011 | 31 |
20.8%
|
|
| 2012 | 76 |
51%
|
|
| 2013 | 11 |
7.4%
|
|
| 9999 | 31 |
20.8%
|
|
| Sysmiss | 31 |