The bar chart below gives information about the number of middle-income families (millions) in the world and in different continents.

The bar chart depicts the number of middle-income families, measured in millions, around the world and across six differents continents in 1950 and 2007, with projections for 2030. The main facts that stand out is that North America had the highest number of middle-income families throughout the period. Standing in contrast, Africa consistently recorded the […]