| Value | Category | Cases | |
|---|---|---|---|
| 2005 | 2 |
0.3%
|
|
| 2006 | 231 |
31.2%
|
|
| 2007 | 273 |
36.9%
|
|
| 2008 | 169 |
22.8%
|
|
| 2009 | 50 |
6.8%
|
|
| 2010 | 10 |
1.4%
|
|
| 9997 | inconsistent | 5 |
0.7%
|
| 9998 | dk | 0 |
0%
|
| 10001 | .Z | 18014 |