| Value | Category | Cases | |
|---|---|---|---|
| 2006 | 2 |
0.3%
|
|
| 2007 | 128 |
17.1%
|
|
| 2008 | 170 |
22.7%
|
|
| 2009 | 151 |
20.2%
|
|
| 2010 | 151 |
20.2%
|
|
| 2011 | 136 |
18.2%
|
|
| 2012 | 10 |
1.3%
|
|
| 9997 | Inconsistent | 0 |
0%
|
| 9999 | Missing | 0 |
0%
|
| Sysmiss | 12 |