| Value | Category | Cases | |
|---|---|---|---|
| -99 | Missing response | 0 |
0%
|
| 2012 | 399 |
25.2%
|
|
| 2013 | 800 |
50.6%
|
|
| 2014 | 383 |
24.2%
|
|
| Sysmiss | 94 |