Interesting data. It's an Australian publication, so I don't know where it sits in the political or legitimacy spectrum. It would be interesting to see what the statistics would be if Australia wasn't a big island, making for a more difficult black market.
Interesting side note was the discussion in the comments section on the Nazis. The anti-gun commenters seem to firmly believe the Nazis were right wing.
http://thenewdaily.com.au/news/2015/11/10/australias-secret-gun-problem-exposed/