The 100% area chart below shows the market share for smartphone vendors based on the numbers of units. Market share for the largest vendors, Samsung & Apple, have been shrinking over the last 4 years. The relative height of each segment (row) at each year (column) depicts the market share.
The 100% area chart is an effective way to show market share without indicating the change in the absolute market size. If we also wanted to show the growth in the overall market, a regular area chart would have been an obvious choice.