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"): Willunga is a town south of Adelaide, South Australia in the City of Onkaparinga local government area 47 km from the Adelaide CBD.
Relevant evidence: No