Conversation so far:
when did the Seekers return to australia?
In March 1967, The Seekers returned to Australia
Are there any other interesting aspects about the Seekers article?
In March 1967, The Seekers returned to Australia for a homecoming tour.
what was the Seekers' homecoming tour?
The homecoming tour included a performance at Music for the People at the Sidney Myer Music Bowl in Melbourne
did the Seekers win any awards?
In 1967, they were named as joint Australians of the Year – the only group thus honoured.
how many people attended the Seekers' homecoming tour?
The Seekers returned to Australia for a homecoming tour, attended by an estimated audience of 200,000.
what did the Seekers do next after their homecoming tour?
The group filmed another TV special, The World of the Seekers.
did the Seekers win any awards?
In January 1968, on Australia Day, the group was named joint Australians of the Year.
why did the Seekers have the honor of being named Australians of the Year?
In recognition of its achievements, the group was named joint Australians of the Year.

Question: which achievements?
Self-contained rewrite: which achievements led to the Seekers being named Australians of the Year?