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
4450
4449
4448
4447
4446
4445
4444
4443
4442
4441
4440
4439
4438
4437
4436
4435
4434
4433
4432
4431
4430