Y \ X
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
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
1840
1839
1838
1837
1836
1835
1834
1833
1832
1831
1830
1829
1828
1827
1826
1825
1824
1823
1822
1821
1820