| Year | Count |
|---|---|
| 1958 | 10 |
| 1970 | 14 |
| 1971 | 14 |
| 1972 | 10 |
| 1974 | 12 |
| 1975 | 20 |
| 1976 | 24 |
| 1977 | 20 |
| 1978 | 18 |
| 1979 | 22 |
| 1980 | 26 |
| 1981 | 20 |
| 1982 | 18 |
| 1983 | 14 |
| 1984 | 16 |
| 1985 | 16 |
| 1986 | 18 |
| 1987 | 12 |
| 1988 | 12 |
| 1990 | 14 |
| 1991 | 22 |
| 1992 | 20 |
| 1993 | 24 |
| 1994 | 14 |
| 1995 | 14 |
| 1996 | 14 |
| 1997 | 23 |
| 1998 | 18 |
| 1999 | 16 |
| 2000 | 22 |
| 2001 | 18 |
| 2002 | 23 |
| 2003 | 55 |
| 2004 | 68 |
| 2005 | 99 |
| 2006 | 78 |
| 2007 | 97 |
| 2008 | 48 |
| 2009 | 21 |
| 2010 | 34 |
| 2011 | 74 |
| 2012 | 63 |
| 2013 | 35 |
| 2014 | 22 |
| 2015 | 15 |
| 2016 | 38 |
| 2017 | 49 |
| 2018 | 52 |
| 2019 | 73 |
| 2020 | 38 |
| 2021 | 61 |
| 2022 | 100 |
| 2023 | 67 |
| 2024 | 66 |