| Value | Category | Cases | |
|---|---|---|---|
| -99 | Don't know | 55 |
44%
|
| 2005 | 1 |
0.8%
|
|
| 2006 | 1 |
0.8%
|
|
| 2007 | 1 |
0.8%
|
|
| 2008 | 2 |
1.6%
|
|
| 2010 | 1 |
0.8%
|
|
| 9888 | Continuing | 64 |
51.2%
|
| Sysmiss | 61 |