This guy nailed it.
Twelve months ago, Horace Dediu predicted that 2015 would be the year that Apple overtook Windows.
Above: His updated chart, showing that Apple devices did indeed outsell Windows PCs in 2015.
Below: The version he posted April 14, 2015, on Asymco.com.
Note that Dediu has titled these charts “the history of the Personal Computer market since 1981,” a bit of graphical slight of hand that mixes apples and oranges. On one hand, he’s broadened the “personal computer” rubric to cover Windows PCs, Macs, iPhones and iPads. On the other, he’s excluded sales of hundreds of millions of Android devices.