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
7000
6999
6998
6997
6996
6995
6994
6993
6992
6991
6990
6989
6988
6987
6986
6985
6984
6983
6982
6981
6980