Y \ X
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
6500
6499
6498
6497
6496
6495
6494
6493
6492
6491
6490
6489
6488
6487
6486
6485
6484
6483
6482
6481
6480