Shark attacks in the United States declined in 2011, but worldwide fatalities reached a two-decade high, according to a new study.

The University of Florida released its annual international shark attack file report Tuesday.

UF reported there were 12 shark fatalities in 2011. They all occurred outside the United States.

“We had a number of fatalities in essentially out-of the way places, where there’s not the same quantity and quality of medical attention readily available,” said UF scientist George Burgess. “They also don’t have histories of shark attacks in these regions, so there are not contingency plans in effect like there are in places such as Florida.”

There were 75 attacks worldwide, which is about average. But the UF study found the number of deaths doubled compared with 2010. Australia had the most deadly attacks with three.

“We’ve had a decade-long decline in the number of attacks and a continued decline in the fatality rate in the U.S.,” Burgess said. “But last year’s slight increase in non-U.S. attacks resulted in a higher death rate. One in four people who were attacked outside the U.S. died.”

There were 29 shark attacks in the United States. Florida led the U.S. with 11 attacks. UF reports that Florida historically leads the U.S. in shark attacks.

Volusia County, which has a high number of surfers, again led the state with six attacks. But that was the lowest number since 2004.