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
4260
4259
4258
4257
4256
4255
4254
4253
4252
4251
4250
4249
4248
4247
4246
4245
4244
4243
4242
4241
4240