| Value | Category | Cases | |
|---|---|---|---|
| 0 | Not given | 161 |
0.9%
|
| 2009 | 1 |
0%
|
|
| 2010 | 16 |
0.1%
|
|
| 2011 | 440 |
2.4%
|
|
| 2012 | 1008 |
5.6%
|
|
| 2013 | 1586 |
8.8%
|
|
| 2014 | 504 |
2.8%
|
|
| 4444 | Marked on card | 98 |
0.5%
|
| Sysmiss | 14294 |
78.9%
|