The Sheffield Urban Area is a conurbation with a population of 685,368 according to the 2011 census. This was a 7% increase on the 2001 population of 640,720 making it the 8th largest conurbation in the United Kingdom and England's 6th largest. Named the Sheffield Urban Area by the Office for National Statistics, it must not be confused with the Sheffield City Region, a non-government term, although often used, particularly by the business community. The conurbation dominates South Yorkshire, with over half of the county's population living in this urban area. In 2001 the population density of the urban area was 3,949.2 people per km2 by 2011 this had increased slightly to 4,092 people per km2.