| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Never regiestered (spontaneous) | 0 |
0%
|
| 1982 | 1 |
0.4%
|
|
| 1988 | 1 |
0.4%
|
|
| 1995 | 2 |
0.8%
|
|
| 1999 | 2 |
0.8%
|
|
| 2000 | 8 |
3.2%
|
|
| 2001 | 3 |
1.2%
|
|
| 2002 | 3 |
1.2%
|
|
| 2003 | 4 |
1.6%
|
|
| 2004 | 3 |
1.2%
|
|
| 2005 | 6 |
2.4%
|
|
| 2006 | 6 |
2.4%
|
|
| 2007 | 2 |
0.8%
|
|
| 2008 | 5 |
2%
|
|
| 2009 | 14 |
5.6%
|
|
| 2010 | 21 |
8.4%
|
|
| 2011 | 9 |
3.6%
|
|
| 2012 | 18 |
7.2%
|
|
| 2013 | 17 |
6.8%
|
|
| 2014 | 25 |
10%
|
|
| 2015 | 32 |
12.8%
|
|
| 2016 | 40 |
16%
|
|
| 2017 | 19 |
7.6%
|
|
| 2018 | 9 |
3.6%
|