year  count
1950    6
1951    7
1952    1
1953   13
1954   13
1955   10
1956    8
1957   13
1958   23
1959   33
1960   13
1961   12
1962   10
1963   13
1964   41
1965   24
1966   25
1967   36
1968   22
1969   38
1970   37
1971   38
1972   30
1973   22
1974   20
1975    8
1976   16
1977   23
1978   13
1979   32
1980   47
1981   22
1982   18
1983   33
1984   43
1985   21
1986   14
1987   16
1988   37
1989   17
1990   10
1991   13
1992   28
1993   39
1994   37
1995    7