| Value | Category | Cases | |
|---|---|---|---|
| 2005 | 1 |
0.1%
|
|
| 2006 | 112 |
15.9%
|
|
| 2007 | 266 |
37.7%
|
|
| 2008 | 216 |
30.6%
|
|
| 2009 | 89 |
12.6%
|
|
| 2010 | 17 |
2.4%
|
|
| 9997 | inconsistent | 4 |
0.6%
|
| 9998 | dk | 0 |
0%
|
| 10001 | .Z | 18049 |