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
4100
4099
4098
4097
4096
4095
4094
4093
4092
4091
4090
4089
4088
4087
4086
4085
4084
4083
4082
4081
4080