four constituent countries of the UK. The NHS in England is by far the largest of the four parts and had a turnover of £92.5 billion in 2008. In 2007/08 higher education institutions in the UK had a total income of £23 billion and employed a total of 169,995 staff. In 2007/08 there were 2,306,000 higher education students in the UK (1,922,180 in England, 210,180 in Scotland, 125,540 in Wales and 48,200 in Northern Ireland). Financial and business services The UK financial services industry added gross value of £116.4 billion to the UK economy in 2011. The UK's exports of financial and business services make a significant positive contribution towards the country's balance of payments. London is a major centre for international business and commerce and is one of the three "command centres" of the global economy (alongside New York City and Tokyo). There are over 500 banks with offices in London, and it is the leading international centre for banking, insurance, Eurobonds, foreign exchange trading and energy futures. London's financial services industry is primarily based in the City of London and Canary Wharf. The City houses the London Stock Exchange, the London Metal Exchange, Lloyd's of London, and the Bank of England. Canary Wharf began development in the 1980s and is now home to major financial institutions such as Barclays Bank, Citigroup and HSBC, as well as the UK Financial Services Authority. London is also a major centre for other business and professional services, and four of the six largest law firms in the world are headquartered there. Several other major UK cities have large financial sectors and related services. Edinburgh has one of the largest financial centres in Europe and is home to the headquarters of Lloyds Banking Group, NatWest Group and Standard Life. Leeds is the UK's largest centre for business and financial services outside London, and the largest centre for legal services in the UK after London. According to a series of research papers and reports published in the mid-2010s, Britain's financial firms provide sophisticated methods to launder billions of pounds annually, including money from the proceeds of corruption around the world as well as the world's drug trade, thus making the city a global hub for illicit finance. According to a Deutsche Bank study published in March 2015, Britain was attracting circa one billion pounds of capital inflows a month not recorded by official statistics,