| Year | Count |
|---|---|
| 1958 | 8 |
| 1959 | 8 |
| 1960 | 7 |
| 1961 | 5 |
| 1962 | 5 |
| 1976 | 5 |
| 1977 | 7 |
| 1979 | 8 |
| 1980 | 5 |
| 1982 | 6 |
| 1987 | 8 |
| 1988 | 5 |
| 1989 | 6 |
| 1990 | 9 |
| 1991 | 11 |
| 1992 | 13 |
| 1993 | 6 |
| 1994 | 7 |
| 1995 | 16 |
| 1996 | 10 |
| 1997 | 16 |
| 1998 | 31 |
| 1999 | 20 |
| 2000 | 16 |
| 2001 | 20 |
| 2002 | 15 |
| 2003 | 18 |
| 2004 | 22 |
| 2005 | 29 |
| 2006 | 25 |
| 2007 | 28 |
| 2008 | 20 |
| 2009 | 31 |
| 2010 | 42 |
| 2011 | 26 |
| 2012 | 36 |
| 2013 | 52 |
| 2014 | 50 |
| 2015 | 40 |
| 2018 | 82 |
| 2019 | 10 |
| 2020 | 43 |
| 2021 | 45 |
| 2023 | 49 |
| 2024 | 66 |