Read this and answer the question. If the question is unanswerable, say "unanswerable".

According to the Sixth China Census, the total population of the City of Nanjing reached 8.005 million in 2010. The statistics in 2011 estimated the total population to be 8.11 million. The birth rate was 8.86 percent and the death rate was 6.88 percent. The urban area had a population of 6.47 million people. The sex ratio of the city population was 107.31 males to 100 females.

How many people were considered to be living in the urban portion of Nanjing?
6.47 million