claim: In fact, the trend, while not statistically significant, is downward.”
evidence: Gartner's own press release said, "Apple continued its downward trend with a decline of 7.7 percent in the second quarter of 2016", which is their decline, based on absolute number of units, that underestimates the relative decline (with the market increasing), along with the misleading "1.7 percent [point]" decline.
category: Usage share of operating systems