| Value | Category | Cases | |
|---|---|---|---|
| 0 | 555 |
83.2%
|
|
| 2 | 1 |
0.1%
|
|
| 3 | 1 |
0.1%
|
|
| 1997 | 1 |
0.1%
|
|
| 1998 | 2 |
0.3%
|
|
| 2003 | 2 |
0.3%
|
|
| 2005 | 1 |
0.1%
|
|
| 2007 | 1 |
0.1%
|
|
| 2008 | 4 |
0.6%
|
|
| 2009 | 1 |
0.1%
|
|
| 2010 | 8 |
1.2%
|
|
| 2011 | 15 |
2.2%
|
|
| 2012 | 30 |
4.5%
|
|
| 2013 | 4 |
0.6%
|
|
| 8888 | 41 |
6.1%
|
|
| Sysmiss | 2716 |