| Value | Category | Cases | |
|---|---|---|---|
| 2006 | 195 |
10.2%
|
|
| 2007 | 343 |
17.9%
|
|
| 2008 | 410 |
21.4%
|
|
| 2009 | 427 |
22.3%
|
|
| 2010 | 395 |
20.6%
|
|
| 2011 | 146 |
7.6%
|
|
| 9997 | Inconsistent | 0 |
0%
|
| 9999 | Missing | 0 |
0%
|
| Sysmiss | 6 |