| Year | Count |
|---|---|
| 1959 | 12 |
| 1975 | 6 |
| 1977 | 5 |
| 1978 | 9 |
| 1983 | 7 |
| 1984 | 11 |
| 1985 | 10 |
| 1986 | 6 |
| 1987 | 11 |
| 1988 | 12 |
| 1989 | 7 |
| 1990 | 19 |
| 1991 | 9 |
| 1992 | 17 |
| 1993 | 13 |
| 1994 | 10 |
| 1995 | 12 |
| 1996 | 8 |
| 1997 | 20 |
| 1998 | 23 |
| 1999 | 13 |
| 2000 | 25 |
| 2001 | 29 |
| 2002 | 25 |
| 2003 | 24 |
| 2004 | 36 |
| 2005 | 35 |
| 2006 | 20 |
| 2007 | 54 |
| 2008 | 45 |
| 2009 | 56 |
| 2010 | 48 |
| 2011 | 52 |
| 2012 | 51 |
| 2013 | 49 |
| 2014 | 58 |
| 2015 | 46 |
| 2023 | 84 |