According to the 2014 United States Census estimates, there were 1,560,297 people residing in the City of Philadelphia, representing a 2.2% increase since 2010. From the 1960s up until 2006, the city's population declined year after year. It eventually reached a low of 1,488,710 residents in 2006 before beginning to rise again. Since 2006, Philadelphia added 71,587 residents in eight years. A study done by the city projected that the population would increase to about 1,630,000 residents by 2035, an increase of about 100,000 from 2010.
When was the low point in Philadelphia's population? (If the question is unanswerable, say "unanswerable")
2006