Note: the September 1940 election outcome is difficult to classify in this format. In a House of Representatives of 74 seats, it saw a hung Parliament. The Coalition and Labor each had 36 seats and independents had two seats. Following the election, the Coalition formed government with the support of the two independents (initially under Robert Menzies and then Arthur Fadden as Prime Minister). A year later, in October 1941, the independents switched their allegiance to Labor with John Curitn as Prime Minister. Curtin went on to win the 1943 election with a sizable majority.
The data for these charts came from Wikipedia.