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
9990
9989
9988
9987
9986
9985
9984
9983
9982
9981
9980
9979
9978
9977
9976
9975
9974
9973
9972
9971
9970