| Year | Count |
|---|---|
| 1952 | 14 |
| 1955 | 10 |
| 1956 | 25 |
| 1957 | 38 |
| 1958 | 49 |
| 1959 | 32 |
| 1960 | 41 |
| 1961 | 49 |
| 1962 | 51 |
| 1963 | 80 |
| 1964 | 72 |
| 1965 | 107 |
| 1966 | 93 |
| 1967 | 146 |
| 1968 | 130 |
| 1969 | 252 |
| 1970 | 333 |
| 1971 | 396 |
| 1972 | 306 |
| 1973 | 307 |
| 1974 | 316 |
| 1975 | 282 |
| 1976 | 352 |
| 1977 | 359 |
| 1978 | 393 |
| 1979 | 329 |
| 1980 | 177 |
| 1981 | 84 |
| 1982 | 60 |
| 1983 | 93 |
| 1984 | 48 |
| 1985 | 65 |
| 1986 | 36 |
| 1987 | 53 |
| 1988 | 75 |
| 1989 | 88 |
| 1990 | 104 |
| 1991 | 94 |
| 1992 | 76 |
| 1993 | 71 |
| 1994 | 90 |
| 1995 | 55 |
| 1996 | 32 |
| 1997 | 19 |
| 1998 | 18 |
| 1999 | 26 |
| 2000 | 30 |
| 2001 | 34 |
| 2002 | 17 |
| 2003 | 36 |
| 2004 | 32 |
| 2005 | 10 |
| 2006 | 12 |
| 2007 | 12 |
| 2009 | 6 |
| 2013 | 10 |
| 2021 | 5 |