KNOXVILLE (WATE) – Gun “super-owners” are on the rise.

According to a study by Harvard and Northeastern University study obtained by the Guardian, three percent of American adults own half of the guns in the United States. This group of 7.7 million “super-owners” has between eight and 140 guns each, according to the survey.

The Census Bureau estimates there are about 247 million adults in the U.S. So according to the survey’s results, 7.7 million Americans own an average of about 17 guns each.

Researchers estimated that America’s gun stock has increased by 70 million guns since 1994. At the same time, the percentage of Americans who own guns decreased slightly from 25 percent to 22 percent. The study also found that there has been a dramatic increase in gun theft, nearly doubling from 230,000 per year to 400,000 per year.

Deborah Azrael, the lead author of the study and a researcher at the Harvard School of Public Health, said, despite the numbers, there was no research on “whether owning a large number of guns is a greater risk factor than owning a few guns.”

The most-often cited reason for owning a firearm is protection from other people, according to the Washington Post. By contrast, in the 1990s most gun owners said they used them for hunting and target-shooting.

“When I look at our survey, what I see is a population that is living in fear,” said Azrael. “They are buying handguns to protect themselves against bad guys, they store their guns ready-to-use because of bad guys, and they believe that their guns make them safer.”

Gun rights advocates are often skeptical of gun-ownership surveys, saying that many owners may not disclose the presence of guns to a stranger over the phone or in person. Survey researchers have generally found little evidence to support this claim. The Harvard-Northeastern survey was conducted anonymously via an online panel. The researchers told the Guardian newspaper that they did not receive any pushback from respondents about the questions, leading them to be confident in the results.