 The average age of a Sotonian was 37.6 years in 2016, ranking Southampton as one of the twenty most youthful cities in the UK.In the 2001 census Southampton and Portsmouth were recorded as being parts of separate urban areas; however by the time of the 2011 census they had merged apolitically to become the sixth-largest built-up area in England with a population of 855,569.This built-up area is part of the metropolitan area known as South Hampshire, which is also sometimes referred to as "Solent City", particularly in the media when discussing development issues and local governance organisational changes.