In what year of the 20th Century did Australia reach the lowest percent of foreign born population?

The first new player to comment on the website with the correct answer wins a free drink at their next iQ Trivia quiz.
In what year of the 20th Century did Australia reach the lowest percent of foreign born population?

The first new player to comment on the website with the correct answer wins a free drink at their next iQ Trivia quiz.
Let’s guess 1945.
White Australia had been in force for a long time, and it was just before the big post-war immigration surge.
You’ve got the right rationale, and are only off by a couple of years.