West London is a sub region of Greater London consisting of the London Boroughs of Brent, Ealing, Hammersmith and Fulham, Harrow, Hillingdon, Hounslow and Richmond upon Thames.West London had a gross value added of 34.4 billion Pound Sterling in 2007, around 20 % of the gross value added of Greater London. London Heathrow Airport is a major employer in West London and the University of West London has more than 47,000 students.