Value | Category | Cases | |
---|---|---|---|
2005 | 2 |
2.8%
|
|
2008 | 2 |
2.8%
|
|
2009 | 51 |
71.8%
|
|
2010 | 4 |
5.6%
|
|
9999 | never back | 12 |
16.9%
|
Sysmiss | 25882 |