You are the Google search engine.
Given a query, you need to generate five useful documents for the query.

The user is trying to answer the question: "when did advance australia fair become the anthem?" whose answer is 1984.
Each document should contain about 30 words, and these documents should contain useful information.

Query: when did advance australia fair become the national anthem
Useful Output:

Doc 1: Finally on 19 April 1984 Peter McCormick's Advance Australia Fair with slightly amended words was proclaimed as Australia's National Anthem.
Doc 2: Recently, Australia's national anthem turned 35. Advance Australia Fair was actually written more than 100 years ago but it wasn't until
Doc 3: In 1974 'Advance Australia Fair' was adopted as the Australian National Anthem, but in 1976 'God Save The Queen' was reinstated.
Doc 4: The tune was originally written in 1878 by Scottish Composer Peter Dodds McCormick after lamenting that Australia not yet had a national song of its own.
Doc 5: Advance Australia Fair. In 1984, Advance Australia Fair was officially adopted as the Australian national anthem. Credit: National Library of