Gday Julia,
A program on TV during the week on ABC I think there was a Liberal party man and a LAbour party man. I don't know their names I don't follow politics much. The very arguement was used above that under Labour 90% are put to the back of the que because they have no papers but under the Liberals that 90% would not be settleled in Australia because they have no proof of who they are. Both the Labour and the Liberal side didn't refute the 90% figure.
I have a customer a lawyer who wrote the United nations refugee laws into Australian law and have asked him many questions about people who come here without papers and Australias obligation. I asked him specifically about the 90% and he said that was about right. Mr McGilvary is from the states and loves baseball. He plays in baseball teams here in Canberra even though he only has one leg.
You are right though most illegial entrants come here on planes.