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
7890
7889
7888
7887
7886
7885
7884
7883
7882
7881
7880
7879
7878
7877
7876
7875
7874
7873
7872
7871
7870