Inner London is the name for the group of London boroughs which form the interior part of Greater London and are surrounded by Outer London. The area was first officially defined in 1965 and for purposes such as statistics, the definition has changed over time. The terms Inner London and Central London cannot be used interchangeably to mean the same area. Inner London is officially the richest area in Europe with the most expensive street in Europe, GDP per capita is nearly $80,000 while the UK GDP per capita is nearly $46,000. Many of the world's richest people live in West and North London, but there is widespread poverty too in these areas as well as the East End and areas south of the river.