When was the Sydney Opera House built?
21611
1973
1973
1973
1973
1973
1973
1973
1973
1973
1973
1973
1973
1973
1964
1973
1964
1973
1964
1973
1964
1973
1964
1970
1973
1964
1970
1973
1964
1970
1972
1973
1964
1970
1972
1969
1964
1970
1972
1969
1964
1976
1970
1972
1969
1964
1976
1970
1972
1969
1964
1976
1970
1959
1972
1969
1964
1976
1970
1959
1972
1969
1964
1976
1970
1931
1959
1971
1970s
1972
1969
1960s
1960
1964
1976
1970
1962
1959
1971
1931
1972
1969
1960
1964
1976
1970
1962
1974
1959
1971
1970s
1972
1969
1960s
1960
1964
1931
1976
1970
1962
1974
1968
1959
1971
1972
1969
1960
1964
1976
1932
1970
1962
1974
1968
1931
1959
1971
1970s
1972
1969
1960s
1966
1960
1964
1976
1970
1962
1974
1968
1959
1932
1907
1971
1909
1931
1972
1969
1973.
1966
1960
1964
1939
1976
1970
1962
1974
1968
1959
1971
1970s
1972
1969
1932
1960s
1966
1907
1960
1909
1931
1976
1975
1973.
1970
1962
1974
1968
1939
1959
1956
1971
1972
1969
1966
1960
1977
1976
1975
1932
1970
1907
1962
1974
1909
1968
1931
1959
1956
1971
1970s
1939
1912
1972
1969
1960s
1966
1960
1977
1976
1975
1973.
1970