Read this: The metro leaves the Rodoviária (bus station) and goes south, avoiding most of the political and tourist areas. The main purpose of the metro is to serve cities, such as Samambaia, Taguatinga and Ceilândia, as well as Guará and Águas Claras. The satellite cities served are more populated in total than the Plano Piloto itself (the census of 2000 indicated that Ceilândia had 344,039 inhabitants, Taguatinga had 243,575, whereas the Plano Piloto had approximately 400,000 inhabitants), and most residents of the satellite cities depend on public transportation.

As of 2000, how many people lived in the Plano Piloto?
What is the answer? (If it cannot be answered, return "unanswerable")
approximately 400,000