Y \ X
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
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
9550
9549
9548
9547
9546
9545
9544
9543
9542
9541
9540
9539
9538
9537
9536
9535
9534
9533
9532
9531
9530