Apple's greatest weakness: iPhone continues to underperform the market as a whole

Apple may have the single best-selling smartphone model in the world, but there is one aspect of its business that you'll never hear CEO Tim Cook mention: The fact that iPhone sales consistently underperform the global market as a whole. iPhone may be the most popular single phone but it is cheaper Android phones that are 88% of all phones sold.

Generally, iPhone sales roughly track the market. But the global smartphone market is approaching saturation, and growth is slowing. That's a problem for Apple, because since 2012 the iPhone has underperformed the rest of the market.

UBS analysts Steven Milunovich and Benjamin Wilson crunched some data from Gartner on smartphone sales and published this set of charts showing where Apple is making gains and where it's losing.

• The good news: Apple is out-performing the market in the US, Europe and Japan.
• The bad news: Apple's sales are still in decline in the US, and doing worse than everyone else in China.

Keep scrolling for the charts. ↓↓↓