1947
3 letters
1949
6 letters
1950
1 letter
1951
3 letters
1952
2 letters
1953
1 letter
1955
9 letters
1956
2 letters
1957
4 letters
1958
11 letters
1960
2 letters
1961
10 letters
1962
1 letter
1963
1 letter
1964
6 letters
1965
10 letters
1966
37 letters
1967
306 letters
1968
539 letters
1969
760 letters
1970
680 letters
1971
619 letters
1972
664 letters
1973
446 letters
1974
750 letters
1975
812 letters
1976
776 letters
1977
347 letters