Well, here is the thing with this survey. November 2014, the iPhone 6/6+ were the only devices with it, and it was only a month old (3 months for the phone). Today, there are 14 months worth of iPhone 6/6+ sales, Apple Watches, and iPhone 6s/6s+ sales. In other words, a larger pool of "eligible" transactions.
What are the raw numbers? How many transactions? Did it go from 100,000 to 1 million, but represent a decline % wise? And what defines an "Apple Pay" eligible transaction? Every transaction made at Apple Pay accepting stores, regardless if the customer has an Apple Pay ready device?
Lots of questions, very light on the facts, and the facts provided tell us almost nothing.