| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 2 |
0.6%
|
| -7 | Never regiestered (spontaneous) | 0 |
0%
|
| 1957 | 1 |
0.3%
|
|
| 1967 | 1 |
0.3%
|
|
| 1968 | 1 |
0.3%
|
|
| 1972 | 1 |
0.3%
|
|
| 1979 | 2 |
0.6%
|
|
| 1982 | 2 |
0.6%
|
|
| 1983 | 1 |
0.3%
|
|
| 1984 | 4 |
1.1%
|
|
| 1988 | 2 |
0.6%
|
|
| 1990 | 1 |
0.3%
|
|
| 1991 | 1 |
0.3%
|
|
| 1994 | 1 |
0.3%
|
|
| 1995 | 5 |
1.4%
|
|
| 1996 | 5 |
1.4%
|
|
| 1997 | 5 |
1.4%
|
|
| 1998 | 7 |
1.9%
|
|
| 1999 | 3 |
0.8%
|
|
| 2000 | 7 |
1.9%
|
|
| 2001 | 5 |
1.4%
|
|
| 2002 | 5 |
1.4%
|
|
| 2003 | 8 |
2.2%
|
|
| 2004 | 8 |
2.2%
|
|
| 2005 | 2 |
0.6%
|
|
| 2006 | 12 |
3.3%
|
|
| 2007 | 7 |
1.9%
|
|
| 2008 | 24 |
6.7%
|
|
| 2009 | 21 |
5.8%
|
|
| 2010 | 23 |
6.4%
|
|
| 2011 | 33 |
9.2%
|
|
| 2012 | 27 |
7.5%
|
|
| 2013 | 19 |
5.3%
|
|
| 2014 | 21 |
5.8%
|
|
| 2015 | 26 |
7.2%
|
|
| 2016 | 29 |
8.1%
|
|
| 2017 | 30 |
8.3%
|
|
| 2018 | 8 |
2.2%
|