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
9910
9909
9908
9907
9906
9905
9904
9903
9902
9901
9900
9899
9898
9897
9896
9895
9894
9893
9892
9891
9890