| Value | Category | Cases | |
|---|---|---|---|
| 0 | 1 |
0.2%
|
|
| 999 | 1 |
0.2%
|
|
| 1997 | 1 |
0.2%
|
|
| 1998 | 1 |
0.2%
|
|
| 2000 | 1 |
0.2%
|
|
| 2001 | 1 |
0.2%
|
|
| 2002 | 1 |
0.2%
|
|
| 2006 | 2 |
0.5%
|
|
| 2008 | 1 |
0.2%
|
|
| 2009 | 3 |
0.7%
|
|
| 2010 | 6 |
1.4%
|
|
| 2011 | 7 |
1.6%
|
|
| 2012 | 7 |
1.6%
|
|
| 2013 | 11 |
2.5%
|
|
| 2014 | 26 |
6%
|
|
| 2015 | 95 |
21.9%
|
|
| 2016 | 252 |
58.2%
|
|
| 9999 | 16 |
3.7%
|
|
| Sysmiss | 158 |