Drone sales are expected to grow from 2.5 million this year to 7 million in 2020, according to report released this week by the Federal Aviation Administration.

Hobbyist sales will more than double from 1.9 million drones in 2016 to 4.3 million in 2020, the agency said. Meanwhile, business sales will triple over the period from 600,000 to 2.7 million.

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The FAA believes that 2017 will be the big turning point in drone adoption by businesses, which use them for everything from scanning power lines to inspecting rooftops for insurance companies. Commercial sales are expected to reach 2.5 million, after which sales will increase only slightly for the next few years.

Currently, companies must obtain FAA certification to fly drones for business purposes. Some businesses and drone lobbying groups have grumbled that the regulation is partly to blame for preventing the drone industry from taking off in the United States.

New rules are in the works that are aimed at streamlining the process for businesses. They are expected to be completed by the later this Spring, the FAA report said.

As of March, the FAA has granted over 3,000 drone-related certifications to businesses.

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The FAA report also shows the markets that the administrations expects will be big users of drones after the regulations are finalized. Industrial inspections will be the biggest use, the agency said, followed by real estate and related aerial photography, agriculture, insurance, and government.