Question: What was the population in the 2011 census of the town that is connected to the towns of Birdwood, Woodside, Balhannah, Hahndorf, and Meadows by Onkaparinga Valley Road?
Sentence (from "Willunga, South Australia"): Sometimes considered a part of the Adelaide metropolitan area, it is located within the famous McLaren Vale wine growing region.
Relevant evidence: No