| Value | Category | Cases | |
|---|---|---|---|
| 1980 | 39 |
0%
|
|
| 1981 | 46 |
0%
|
|
| 1982 | 152 |
0.1%
|
|
| 1983 | 281 |
0.2%
|
|
| 1984 | 453 |
0.3%
|
|
| 1985 | 578 |
0.4%
|
|
| 1986 | 883 |
0.6%
|
|
| 1987 | 1196 |
0.8%
|
|
| 1988 | 1665 |
1.1%
|
|
| 1989 | 2209 |
1.4%
|
|
| 1990 | 2919 |
1.8%
|
|
| 1991 | 3060 |
1.9%
|
|
| 1992 | 4034 |
2.6%
|
|
| 1993 | 4052 |
2.6%
|
|
| 1994 | 4233 |
2.7%
|
|
| 1995 | 5023 |
3.2%
|
|
| 1996 | 5107 |
3.2%
|
|
| 1997 | 5619 |
3.6%
|
|
| 1998 | 6111 |
3.9%
|
|
| 1999 | 6394 |
4%
|
|
| 2000 | 6764 |
4.3%
|
|
| 2001 | 6312 |
4%
|
|
| 2002 | 6344 |
4%
|
|
| 2003 | 6822 |
4.3%
|
|
| 2004 | 6795 |
4.3%
|
|
| 2005 | 7304 |
4.6%
|
|
| 2006 | 6920 |
4.4%
|
|
| 2007 | 6749 |
4.3%
|
|
| 2008 | 6778 |
4.3%
|
|
| 2009 | 6818 |
4.3%
|
|
| 2010 | 7140 |
4.5%
|
|
| 2011 | 5726 |
3.6%
|
|
| 2012 | 5563 |
3.5%
|
|
| 2013 | 4847 |
3.1%
|
|
| 2014 | 4129 |
2.6%
|
|
| 2015 | 3554 |
2.3%
|
|
| 2016 | 2688 |
1.7%
|
|
| 2017 | 2135 |
1.4%
|
|
| 2018 | 185 |
0.1%
|
|
| 9997 | Inconsistent | 104 |
0.1%
|
| 9999 | No response | 168 |
0.1%
|