Complex sentence: The Avery Building was the headquarters of the New South Wales Police Force, Australia from the 1970s until 2004, when a new headquarters building was opened at Parramatta in conjunction with police executive offices located in Elizabeth Street, Sydney.
Split into simpler sentences: The Avery Building was the headquarters of the New South Wales Police Force from the 1970s until 2004. At this time a new headquarters building was opened at Parramatta in conjunction with police executive offices located in Elizabeth Street, Sydney.