1. The Group of 20 was founded in 1999 for finance ministers and central bankers, but the onset of the financial crisis in 2008 transformed into a forum for national leaders.
2. This is the eighth G20 leaders' summit. Two of the first three were held in the US and last year's event took place in St Petersburg.
3. The 19 countries and European Union bloc – represented by the European Commission and European Central Bank - that comprise the G20 accounted for 85.9 per cent of the world's economy in 2013, down from 87.7 per cent in 2009.
Read the other 17 facts here.