Yeah, the cost of living in some of our major cities is pretty high, and our dollar is worth less than that in the US; what can be bought at a grocery store for $1USD would be about $2AUD over here. (AUD is usually worth about 50% less than USD in exchange, too.)
Add to that the fact that minimum wage is around $22, and you have yourself some higher industry standard rates.
That said, I only wish I was earning close to what that chart represented! I keep it bookmarked because I aim to work with publishers one day, and want to make sure I'm paid fairly. At the moment, I'm still just chipping away at my own comic, and taking the odd commission on the side.