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
12870
12869
12868
12867
12866
12865
12864
12863
12862
12861
12860
12859
12858
12857
12856
12855
12854
12853
12852
12851
12850