Apple only shares how many iPhones are sold globally per quarter and doesn’t break down sales by model. Consumer Intelligence Research Partners analysis, however, puts the overall US install base at 141 million units compared to 136 million units during the prior quarter and 124 million units in the same quarter a year ago.

The gradual increase follows the same trend for Apple’s iPhone install base among Americans while the breakdown by iPhone model is starting to shift to newer models while older iPhones are phased out.

CIRP believes the iPhone 7 and iPhone 7 Plus, the latest flagships, make up roughly one out of every three iPhones used in the United States with 48 million units in use and 34% of the breakdown.

That’s just barely more iPhone 7 and iPhone 7 Plus models in use compared to the iPhone 6s and iPhone 6s Plus which CIRP believes make up 47 million units. As for the original large screened iPhones, the iPhone 6 and iPhone 6 Plus collectively account for 39 million units being used in the United States according to the data.

Older hardware like the iPhone 5s, iPhone 5c, and iPhone 5 hardly show up on the chart, but the year old iPhone SE saw some growth at 6% of the US install base. That still means that the overwhelming majority of iPhones in use in the United States have larger displays and were released in the last few years.

CIRP’s data shows that the 5.5-inch iPhone is seeing greater adoption in the US year-over-year as well with 53 million units being the iPhone 6 Plus, iPhone 6s Plus, or iPhone 7 Plus. That number represents a 9% increase from 29% to 38% of the install base YOY.

Starting with the iPhone 8 possibly as soon as next month, Apple is expected to introduce an even larger display at 5.8-inches although the nearly bezel-less design will feature a more narrow and taller aspect ratio than the current Plus models.