| Year | Count |
|---|---|
| 1952 | 6 |
| 1954 | 5 |
| 1955 | 10 |
| 1956 | 38 |
| 1957 | 51 |
| 1958 | 10 |
| 1959 | 68 |
| 1960 | 36 |
| 1961 | 152 |
| 1962 | 100 |
| 1963 | 146 |
| 1964 | 131 |
| 1965 | 65 |
| 1966 | 148 |
| 1967 | 170 |
| 1968 | 152 |
| 1969 | 162 |
| 1970 | 235 |
| 1971 | 238 |
| 1972 | 190 |
| 1973 | 155 |
| 1974 | 110 |
| 1975 | 133 |
| 1976 | 177 |
| 1977 | 163 |
| 1978 | 147 |
| 1979 | 139 |
| 1980 | 114 |
| 1981 | 113 |
| 1982 | 119 |
| 1983 | 132 |
| 1984 | 152 |
| 1985 | 152 |
| 1986 | 114 |
| 1987 | 152 |
| 1988 | 50 |
| 1989 | 49 |
| 1990 | 91 |
| 1991 | 51 |
| 1992 | 42 |
| 1993 | 45 |
| 1994 | 44 |
| 1995 | 14 |
| 1996 | 17 |
| 1997 | 8 |
| 2000 | 21 |
| 2001 | 5 |
| 2003 | 10 |
| 2004 | 15 |
| 2007 | 5 |
| 2010 | 5 |
| 2011 | 5 |