| Value | Category | Cases | |
|---|---|---|---|
| 1979 | 2 |
0.5%
|
|
| 1981 | 2 |
0.5%
|
|
| 1982 | 3 |
0.7%
|
|
| 1983 | 4 |
1%
|
|
| 1984 | 6 |
1.5%
|
|
| 1985 | 4 |
1%
|
|
| 1986 | 7 |
1.7%
|
|
| 1987 | 9 |
2.2%
|
|
| 1988 | 8 |
2%
|
|
| 1989 | 8 |
2%
|
|
| 1990 | 16 |
4%
|
|
| 1991 | 14 |
3.5%
|
|
| 1992 | 9 |
2.2%
|
|
| 1993 | 19 |
4.7%
|
|
| 1994 | 19 |
4.7%
|
|
| 1995 | 17 |
4.2%
|
|
| 1996 | 14 |
3.5%
|
|
| 1997 | 17 |
4.2%
|
|
| 1998 | 25 |
6.2%
|
|
| 1999 | 14 |
3.5%
|
|
| 2000 | 21 |
5.2%
|
|
| 2001 | 17 |
4.2%
|
|
| 2002 | 19 |
4.7%
|
|
| 2003 | 16 |
4%
|
|
| 2004 | 20 |
5%
|
|
| 2005 | 15 |
3.7%
|
|
| 2006 | 18 |
4.5%
|
|
| 2007 | 14 |
3.5%
|
|
| 2008 | 21 |
5.2%
|
|
| 2009 | 14 |
3.5%
|
|
| 2010 | 12 |
3%
|