The Pew Research Center reports that tablet ownership among American adults has doubled in the past year, from 11 percent to 22 percent. An additional three percent regularly use a tablet owned by someone else, meaning a full quarter of American adults now have access to a tablet.

Among them, more than half – 52 percent – use an iPad, while 48 percent use some variation of an Android-based tablet, including 21 percent who use a Kindle Fire. That’s a marked downturn in overall marketshare for Apple, which owned 81 percent of the market in 2011. Apple’s still moving quite a large number of iPads, but the market has grown and lower-priced Android tablet makers have sought to fill the gap.

The study suggests that there is some brand loyalty among tablet owners, too – 57 percent of iPad users also use an iPhone, while 66 percent of Android tablet users also have an Android-based phone.

It’ll be interesting to see how this trend is affected if and when Apple introduces the oft-rumored iPad mini.