| Year | Count |
|---|---|
| 1974 | 6 |
| 1978 | 5 |
| 1985 | 14 |
| 1986 | 5 |
| 1987 | 6 |
| 1989 | 5 |
| 1989 | 5 |
| 1990 | 10 |
| 1991 | 5 |
| 1993 | 5 |
| 1994 | 15 |
| 1994 | 5 |
| 1995 | 10 |
| 1995 | 5 |
| 1996 | 44 |
| 1996 | 5 |
| 1997 | 34 |
| 1997 | 5 |
| 1998 | 73 |
| 1998 | 11 |
| 1999 | 20 |
| 2000 | 10 |
| 2000 | 7 |
| 2001 | 12 |
| 2001 | 6 |
| 2002 | 15 |
| 2003 | 17 |
| 2003 | 11 |
| 2004 | 35 |
| 2005 | 5 |
| 2006 | 10 |
| 2008 | 7 |
| 2009 | 7 |
| 2010 | 6 |
| 2012 | 7 |
| 2013 | 7 |
| 2014 | 8 |
| 2015 | 16 |