Shark attacks hit an all time high last year, with the United States leading all nations in numbers of such attacks, according to the University of Florida's International Shark Attack File.

Climate change, recovering shark populations and more people in the water help to explain the high number of recorded shark attacks for 2015: 98, including six fatalities. All of the attacks were unprovoked.

"Sharks plus humans equals attacks," George Burgess, curator of the file, which houses the globe's clearinghouse of shark attack data, said in a press release. "As our population continues to rapidly grow and shark populations slowly recover, we’re going to see more interactions."

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2015 broke the prior record, which was set in 2000. That year, there were 88 attacks. 2015 further saw double the number of deaths from shark attacks versus 2014.

Two of 2015's six fatalities happened off the Indian Ocean island of Réunion, bringing its total deaths to seven since 2011. Australia, Egypt, New Caledonia and the United States each had single fatalities.

The United States, with its abundant coastlines and ever-growing numbers of recreational water users had 59 unprovoked shark attacks reported last year. Australia and South Africa had the second and third largest numbers of attacks, with 18 and eight respectively.

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Within the United States, Florida had the most shark attacks of any state, with 30. North and South Carolina had the next greatest, with eight apiece. Hawaii saw seven attacks and had the country's only fatality. The remaining U.S. incidents for 2015 occurred in California, Texas, Mississippi and New York.

Burgess explained that climate change is warming ocean waters, causing water temperatures to spike earlier in the season and to warm a larger range of coastline. The conditions have been a draw to both sharks and humans.

"We can and should expect the number of attacks to be higher each year," he said. "When we visit the sea, we're on their turf."

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To avoid adding to the yearly tally, Burgess and his team advise not to swim at dusk, dawn or night. They also say not to wear shiny jewelry in the water, and not to swim where people are fishing, where fish are schooling or where seabirds are feeding.

If you are attacked, Burgess said to hit the shark on the nose and to claw at its eyes and gills to scare it away.

Even with 2015's record-breaking number of shark attacks, your chances of experiencing such a risky encounter are very slim. Burgess reminded that the following culprits killed more people than sharks last year: spiders, dogs and lightning.