I think it depends on the people's preferance and the availibility of breeds rather than the suburb. You would think block size would enter into it, but not necessarily. I know of people in units and on small blocks who have large dogs and people on large, rural blocks who have small dogs. Certain decades seem have an abundance of certain breeds, like at one time there were lots of Australian Silky Terriers. and then there was an abundance of German Shepherds, and a little later Rottweilers became popular and now staffies are a popular breed. Price is obviously going to be a big factor and whether the buyer wants a large, medium or small dog. I'm not sure if a lot of people think too much about the grooming/care aspect? I see all sorts of breeds of dog, where ever I go however so people vary in what they prefer. Hopefully, which ever dog they pick, they treat them as a valued, cared for, member of the family and take the time to understand and train them.