| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 3 |
2%
|
| -7 | Never regiestered (spontaneous) | 0 |
0%
|
| 1924 | 1 |
0.7%
|
|
| 1935 | 1 |
0.7%
|
|
| 1948 | 1 |
0.7%
|
|
| 1956 | 1 |
0.7%
|
|
| 1961 | 1 |
0.7%
|
|
| 1966 | 1 |
0.7%
|
|
| 1968 | 1 |
0.7%
|
|
| 1969 | 1 |
0.7%
|
|
| 1978 | 1 |
0.7%
|
|
| 1979 | 1 |
0.7%
|
|
| 1980 | 1 |
0.7%
|
|
| 1983 | 1 |
0.7%
|
|
| 1989 | 1 |
0.7%
|
|
| 1991 | 2 |
1.3%
|
|
| 1993 | 2 |
1.3%
|
|
| 1994 | 1 |
0.7%
|
|
| 1995 | 2 |
1.3%
|
|
| 1998 | 2 |
1.3%
|
|
| 1999 | 4 |
2.7%
|
|
| 2000 | 3 |
2%
|
|
| 2001 | 2 |
1.3%
|
|
| 2002 | 2 |
1.3%
|
|
| 2003 | 2 |
1.3%
|
|
| 2005 | 6 |
4%
|
|
| 2006 | 4 |
2.7%
|
|
| 2007 | 6 |
4%
|
|
| 2008 | 7 |
4.7%
|
|
| 2009 | 4 |
2.7%
|
|
| 2010 | 3 |
2%
|
|
| 2011 | 1 |
0.7%
|
|
| 2012 | 11 |
7.4%
|
|
| 2013 | 3 |
2%
|
|
| 2014 | 5 |
3.4%
|
|
| 2015 | 13 |
8.7%
|
|
| 2016 | 11 |
7.4%
|
|
| 2017 | 17 |
11.4%
|
|
| 2018 | 20 |
13.4%
|