| Value | Category | Cases | |
|---|---|---|---|
| 2005 | 2 |
0.3%
|
|
| 2006 | 230 |
31.3%
|
|
| 2007 | 272 |
37%
|
|
| 2008 | 169 |
23%
|
|
| 2009 | 48 |
6.5%
|
|
| 2010 | 9 |
1.2%
|
|
| 9997 | inconsistent | 6 |
0.8%
|
| 9998 | dk | 0 |
0%
|
| 10001 | .Z | 18018 |