| Year | Count |
|---|---|
| 1956 | 5 |
| 1961 | 6 |
| 1962 | 5 |
| 1965 | 6 |
| 1966 | 7 |
| 1967 | 11 |
| 1968 | 8 |
| 1969 | 6 |
| 1970 | 17 |
| 1971 | 35 |
| 1972 | 14 |
| 1973 | 21 |
| 1974 | 20 |
| 1975 | 19 |
| 1976 | 15 |
| 1977 | 62 |
| 1978 | 54 |
| 1979 | 32 |
| 1980 | 44 |
| 1981 | 31 |
| 1982 | 26 |
| 1983 | 34 |
| 1984 | 45 |
| 1985 | 48 |
| 1986 | 54 |
| 1987 | 64 |
| 1988 | 61 |
| 1989 | 65 |
| 1990 | 97 |
| 1991 | 56 |
| 1992 | 139 |
| 1993 | 168 |
| 1994 | 132 |
| 1995 | 104 |
| 1996 | 101 |
| 1997 | 63 |
| 1998 | 54 |
| 1999 | 84 |
| 2000 | 95 |
| 2001 | 96 |
| 2002 | 75 |
| 2003 | 90 |
| 2004 | 96 |
| 2005 | 75 |
| 2006 | 120 |
| 2007 | 128 |
| 2008 | 108 |
| 2009 | 68 |
| 2010 | 101 |
| 2011 | 100 |
| 2012 | 61 |
| 2013 | 109 |
| 2014 | 93 |
| 2015 | 129 |
| 2016 | 145 |
| 2017 | 116 |
| 2018 | 73 |
| 2019 | 127 |
| 2020 | 155 |
| 2021 | 160 |
| 2022 | 160 |
| 2023 | 188 |
| 2024 | 246 |