What percent does NZ take up out of Australasia?

Answer 1

That depends on your definition of "Australasia". It has sometimes been used as a synonym for the more modern continental term, "Australia and Oceania", which includes Australia, New Zealand, New Guinea, and a large number of other Pacific island countries. In the early part of the 20th century, Australasia was used as a descriptive for athletic teams that were made up of members from both Australia and New Zealand -- such combined teams competed in the 1908 and 1912 Olympics, and Davis cup competitions of that period as well. A quote from Wikipedia's page on Australasia:

"There are many organisations whose names are prefixed with "(Royal) Australasian Society" that are limited to just Australia and New Zealand."

New Zealand's area is 268,700 sqare kilometers. Australia's area is 7,741,000 square kilometers. The combined area of all other countries in "Australia and Oceania" is about 590,000 square kilometers (about 462,800 of which are New Guinea).

If you limit Australasia to only Australia and New Zealand, then New Zealand's percentage would be 3.4%. If you include all the rest of Oceania, then New Zealand's percentage would be 3.1%.