The Economist produced a graph showing world GDP data and made the following points:

• India and China account for 65% of world growth
• Emerging markets contributions in 2016 were down to its lowest figure since 2008 – falling commodity prices would have been a factor
• Norway contributed less to global GDP with lower oil prices being prevalent.
• USA with increased government spending and greater export volumes improved its position
• Brazil has been in negative territory since mid 2014 – interesting point with significant government spending on hosting the Football World Cup and the Olympics.

Maybe a good starter for your classes asking the question who contributes most to world GDP?