Apple could see a significant reduction in its iPhone sales next year, according to Morgan Stanley analyst Katy Huberty. The phone has seen an increase in sales each year since the first iPhone came out, but that trend isn't going to continue if Huberty is correct.

The analyst says iPhone sales will decrease by 5.7% during fiscal year 2016, which comes out to 218 million iPhones. In fiscal year 2015, Apple sold 231.1 million phone units.

Huberty considers this large drop to be a worst case scenario for Apple, making a smaller decline more likely. The drop is attributed to market saturation around the world that will limit the number of new units Apple can push on consumers.