| Year | Count |
|---|---|
| 1956 | 5 |
| 1964 | 5 |
| 1969 | 5 |
| 1970 | 5 |
| 1973 | 8 |
| 1974 | 11 |
| 1975 | 7 |
| 1976 | 9 |
| 1977 | 10 |
| 1978 | 10 |
| 1979 | 8 |
| 1980 | 9 |
| 1981 | 7 |
| 1982 | 7 |
| 1983 | 15 |
| 1984 | 19 |
| 1985 | 23 |
| 1986 | 18 |
| 1987 | 21 |
| 1988 | 16 |
| 1989 | 19 |
| 1990 | 34 |
| 1991 | 28 |
| 1992 | 25 |
| 1993 | 38 |
| 1994 | 25 |
| 1995 | 34 |
| 1996 | 40 |
| 1997 | 29 |
| 1998 | 29 |
| 1999 | 35 |
| 2000 | 32 |
| 2001 | 47 |
| 2002 | 58 |
| 2003 | 44 |
| 2004 | 51 |
| 2005 | 74 |
| 2006 | 59 |
| 2007 | 59 |
| 2008 | 82 |
| 2009 | 88 |
| 2010 | 89 |
| 2011 | 91 |
| 2012 | 79 |
| 2013 | 111 |
| 2014 | 103 |
| 2015 | 123 |
| 2016 | 162 |
| 2017 | 121 |
| 2018 | 141 |
| 2019 | 149 |
| 2020 | 93 |
| 2021 | 103 |
| 2022 | 122 |
| 2023 | 133 |
| 2024 | 128 |