| Value | Category | Cases | |
|---|---|---|---|
| 2006 | 3 |
11.5%
|
|
| 2007 | 4 |
15.4%
|
|
| 2008 | 3 |
11.5%
|
|
| 2009 | 5 |
19.2%
|
|
| 2010 | 11 |
42.3%
|
|
| 9997 | inconsistent | 0 |
0%
|
| 9998 | dk | 0 |
0%
|
| 10001 | .Z | 18728 |