| Year | Count |
|---|---|
| 1960 | 16 |
| 1961 | 7 |
| 1965 | 16 |
| 1966 | 31 |
| 1967 | 52 |
| 1968 | 48 |
| 1969 | 117 |
| 1970 | 209 |
| 1971 | 213 |
| 1972 | 240 |
| 1973 | 330 |
| 1974 | 311 |
| 1975 | 337 |
| 1976 | 319 |
| 1977 | 269 |
| 1978 | 274 |
| 1979 | 251 |
| 1980 | 199 |
| 1981 | 169 |
| 1982 | 177 |
| 1983 | 104 |
| 1984 | 123 |
| 1985 | 164 |
| 1986 | 174 |
| 1987 | 144 |
| 1988 | 92 |
| 1989 | 33 |
| 1990 | 27 |
| 1991 | 38 |
| 1992 | 17 |
| 1993 | 44 |
| 1994 | 40 |
| 1995 | 32 |
| 1996 | 43 |
| 1997 | 18 |
| 1998 | 54 |
| 1999 | 20 |
| 2000 | 5 |
| 2001 | 21 |
| 2002 | 10 |
| 2003 | 6 |
| 2004 | 12 |
| 2005 | 62 |
| 2006 | 39 |
| 2007 | 10 |
| 2008 | 59 |
| 2009 | 6 |
| 2010 | 24 |
| 2011 | 18 |
| 2012 | 5 |
| 2013 | 6 |
| 2015 | 10 |
| 2016 | 27 |
| 2017 | 5 |
| 2019 | 18 |
| 2020 | 18 |
| 2021 | 40 |
| 2022 | 14 |
| 2023 | 24 |
| 2023 | 5 |
| 2024 | 34 |
| 2024 | 6 |