| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 3 |
0.8%
|
| -7 | Never regiestered (spontaneous) | 0 |
0%
|
| 1933 | 1 |
0.3%
|
|
| 1990 | 2 |
0.5%
|
|
| 1991 | 6 |
1.6%
|
|
| 1992 | 8 |
2.1%
|
|
| 1993 | 12 |
3.2%
|
|
| 1994 | 23 |
6.1%
|
|
| 1995 | 14 |
3.7%
|
|
| 1996 | 14 |
3.7%
|
|
| 1997 | 10 |
2.7%
|
|
| 1998 | 15 |
4%
|
|
| 1999 | 9 |
2.4%
|
|
| 2000 | 16 |
4.2%
|
|
| 2001 | 11 |
2.9%
|
|
| 2002 | 10 |
2.7%
|
|
| 2003 | 20 |
5.3%
|
|
| 2004 | 12 |
3.2%
|
|
| 2005 | 11 |
2.9%
|
|
| 2006 | 22 |
5.8%
|
|
| 2007 | 14 |
3.7%
|
|
| 2008 | 16 |
4.2%
|
|
| 2009 | 13 |
3.4%
|
|
| 2010 | 10 |
2.7%
|
|
| 2011 | 14 |
3.7%
|
|
| 2012 | 12 |
3.2%
|
|
| 2013 | 15 |
4%
|
|
| 2014 | 15 |
4%
|
|
| 2015 | 16 |
4.2%
|
|
| 2016 | 20 |
5.3%
|
|
| 2017 | 13 |
3.4%
|