| Year | Count |
|---|---|
| 1958 | 5 |
| 1962 | 6 |
| 1963 | 5 |
| 1964 | 5 |
| 1977 | 10 |
| 1981 | 12 |
| 1983 | 16 |
| 1985 | 5 |
| 1987 | 17 |
| 1988 | 38 |
| 1989 | 17 |
| 1990 | 37 |
| 1991 | 15 |
| 1992 | 11 |
| 1993 | 25 |
| 1994 | 5 |
| 1995 | 15 |
| 1996 | 5 |
| 1997 | 16 |
| 1998 | 19 |
| 1999 | 48 |
| 2000 | 90 |
| 2001 | 69 |
| 2002 | 67 |
| 2003 | 40 |
| 2004 | 43 |
| 2005 | 37 |
| 2006 | 50 |
| 2007 | 74 |
| 2008 | 119 |
| 2009 | 61 |
| 2010 | 28 |
| 2011 | 38 |
| 2012 | 26 |
| 2013 | 5 |
| 2014 | 12 |
| 2017 | 6 |
| 2018 | 10 |
| 2023 | 5 |