Apple mobile operating system iOS ended 2016 with a 14% share of new mobile devices used in Kindergarten through 12th grade, down from 26% in 2014, according to new data from research firm Futuresource Consulting. Meanwhile, Apple’s computer-only operating systems OS X and macOS fell to a 5% share in 2016 from 8% two years earlier.

As Apple’s (AAPL) hold on the education world declined, Google (GOOG) has grown the share of its cloud-based operating system, Chrome OS, to 58% from 38% in 2014. Microsoft stabilized the market share of its Windows operating system in education last year at 22%, flat from 2015 and down from 25% in 2014.

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The findings are troubling for Apple considering that the education market is growing rapidly and presents a major opportunity for technology companies because of its size. Apple once had a strong position in schools thanks to its iPad, but its tablet’s high prices appear to be stunting sales.

Device makers shipped 12.6 million mobile computers—laptops, tablets, and smartphones—to U.S. schools last year, according to Futuresource. In 2015, that number was 10.7 million.

Futuresource’s data looks at electronics shipped to U.S. schools including mobile devices like notebooks, netbooks, and tablets. But it does not include desktop computers.

Apple, which has emphasized its commitment to the education market for years, acquired LearnSprout, a software company that helps teachers monitor and track student performance, in 2016. It came on the heels of Apple announcing several school-friendly improvements to iOS, including adding the ability for a single device to have multiple user accounts so that students could share it.

But, increasingly, Google has a stronger appeal in schools.

According to Futuresource, Google’s combination of cheaper devices, called Chromebooks, which use Chrome OS, along with its software services, have given it a lift with educators. Google Classroom, a software tool designed for schools, is also popular, according to Futuresource.

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Additionally, Microsoft has improved devices and services for the education market, according to Futuresource. But it’s been unable to stop Google’s rise.

Apple’s biggest problem may be the higher prices for its devices compared to its competition. Some schools said this year that they bought Chromebooks for as little as $120, a huge savings over Apple’s iPads, which cost hundreds of dollars more.

“At the end of the day, I can get three Chromebooks for each of the Mac devices I would have purchased,” Steve Splichal, the superintendent of Eudora Public Schools in Kansas told The New York Times in an interview published on Thursday.

Apple is doing little better in schools overseas, where its iOS market share was 9% last year. Microsoft still dominates the international market with a 65% share. Google’s mobile operating systems Android and Chrome OS combined for 23% market share last year outside the country.