| Year | Count |
|---|---|
| 1954 | 5 |
| 1957 | 16 |
| 1964 | 5 |
| 1972 | 5 |
| 1985 | 5 |
| 1987 | 34 |
| 1988 | 20 |
| 1989 | 31 |
| 1990 | 44 |
| 1991 | 38 |
| 1992 | 101 |
| 1993 | 96 |
| 1994 | 148 |
| 1995 | 208 |
| 1996 | 189 |
| 1997 | 212 |
| 1998 | 217 |
| 1999 | 155 |
| 2000 | 186 |
| 2001 | 90 |
| 2002 | 100 |
| 2003 | 128 |
| 2004 | 114 |
| 2005 | 122 |
| 2006 | 70 |
| 2007 | 83 |
| 2008 | 58 |
| 2009 | 64 |
| 2010 | 49 |
| 2011 | 19 |
| 2013 | 5 |
| 2014 | 11 |
| 2017 | 5 |
| 2018 | 5 |