The latest data from Mixpanel shows that approximately 32.22% of active iPhone users still have a 4-inch screen. That is the same screen size as the so-called "iPhone 5se" that Apple is expected to announce at its rumored March 15 event.

Apple has released three iPhone models with 4-inch screens since 2013, including the iPhone 5, iPhone 5c, and iPhone 5s, and some customers still feel these smartphones have the best screen size for pocketability and one-handed usage.



Apple's newest 4-inch smartphone, the iPhone 5s, represented just under 20 percent of current iPhones in use, trailed by the iPhone 5 at 7.53 percent and the plastic-backed iPhone 5c at 5.66 percent. The numbers fluctuate slightly in real time.

In the company's latest earnings call, Apple CEO Tim Cook said that 60 percent of older-generation iPhone users have yet to upgrade to the iPhone 6, iPhone 6 Plus, iPhone 6s, or iPhone 6s Plus.

Right now, customers that want a 4-inch iPhone have to settle for the over two-year-old iPhone 5s's outdated tech specs, and the smartphone also lacks many new features such as Apple Pay, 3D Touch, and Live Photos.

For that reason, the "iPhone 5se" with a rumored 4-inch screen, Apple's newest A9 chip, Live Photos, and purported price of around $500 may prove to be a more popular option among prospective iPhone buyers.