| Value | Category | Cases | |
|---|---|---|---|
| 1968 | 1 |
0.4%
|
|
| 1980 | 3 |
1.2%
|
|
| 1982 | 1 |
0.4%
|
|
| 1984 | 2 |
0.8%
|
|
| 1988 | 1 |
0.4%
|
|
| 1990 | 6 |
2.4%
|
|
| 1992 | 1 |
0.4%
|
|
| 1994 | 2 |
0.8%
|
|
| 1995 | 4 |
1.6%
|
|
| 1997 | 1 |
0.4%
|
|
| 1998 | 2 |
0.8%
|
|
| 2000 | 4 |
1.6%
|
|
| 2002 | 2 |
0.8%
|
|
| 2003 | 1 |
0.4%
|
|
| 2004 | 3 |
1.2%
|
|
| 2006 | 2 |
0.8%
|
|
| 2007 | 5 |
2%
|
|
| 2009 | 11 |
4.3%
|
|
| 2010 | 22 |
8.7%
|
|
| 2011 | 8 |
3.1%
|
|
| 2012 | 16 |
6.3%
|
|
| 2013 | 16 |
6.3%
|
|
| 2014 | 23 |
9.1%
|
|
| 2015 | 51 |
20.1%
|
|
| 2016 | 40 |
15.7%
|
|
| 2017 | 26 |
10.2%
|
|
| Sysmiss | 799 |