| Value | Category | Cases | |
|---|---|---|---|
| 1972 | 1 |
1%
|
|
| 1988 | 1 |
1%
|
|
| 1992 | 1 |
1%
|
|
| 1993 | 1 |
1%
|
|
| 1997 | 3 |
3%
|
|
| 2000 | 7 |
6.9%
|
|
| 2001 | 4 |
4%
|
|
| 2003 | 2 |
2%
|
|
| 2005 | 5 |
5%
|
|
| 2006 | 3 |
3%
|
|
| 2007 | 7 |
6.9%
|
|
| 2008 | 12 |
11.9%
|
|
| 2009 | 13 |
12.9%
|
|
| 2010 | 12 |
11.9%
|
|
| 2011 | 12 |
11.9%
|
|
| 2012 | 6 |
5.9%
|
|
| 2013 | 11 |
10.9%
|
|
| Sysmiss | 366 |