My count of hits by Australian artists in the Melbourne Charts 1960-89, based on the material in Guest, Thomas J. (1991). Thirty Years of Hits. Collingwood, Melbourne: M. J. Maloney. ISBN 0-646-04633-0. Done for my Masters thesis in 1992 (later published as Groenewegen, D., (1997) ‘The Real Thing’? The Rock Music Industry and the Creation of Australian Images 1958-87, Moonlight Press, Melbourne - I'll stick it all on the web one day).
I had quite strong views on what an "Australian" artist was at the time, so artists such as the Bee Gees and Olivia Newton-John are not included. This might make it difficult to replicate the data if you use the same very manual process.