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
2520
2519
2518
2517
2516
2515
2514
2513
2512
2511
2510
2509
2508
2507
2506
2505
2504
2503
2502
2501
2500