Sharks killed four people and bit 58 others around the world in 2006, a comparatively dull year for dangerous encounters between the two species, scientists said in their annual shark attack census on Tuesday. "We love dull years because it means there are fewer serious attacks and fewer victims," said George Burgess, director of the International Shark Attack File at the University of Florida.The number of shark attacks worldwide increased to 62 in 2006 from 61 the previous year but the number of those proving deadly was unchanged at four. That was far below the 79 attacks, 11 of them fatal, in 2000, the researchers said.Despite the frenzy of attention shark attacks receive, the numbers show they are a rare phenomenon."It's really quite remarkable when you have only four people a year die in the mouth of a shark," Burgess said. "The reality is, as a biologist, this is a non-problem. It's a minor, minor thing."Sharkbite numbers grew steadily over the last century as humans reproduced exponentially and spent more time at the seashore. But the numbers have been flat over the past five years as overfishing thinned the shark population near shore and swimmers got smarter about the risks of wading into certain areas, Burgess said."This is the wild world we're entering, not a swimming pool," he said.As usual, the United States had more shark attacks than any other nation, with 38 last year. That was down from 40 the previous year and well below the 53 recorded in 2000.Florida, with its long coastline and year-round swimming weather, accounted for nearly two-thirds of the U.S. tally, but there were no sharkbite fatalities in the United States last year.The four deaths were in waters off Australia, Brazil, the Indian Ocean island of Reunion Island and the South Pacific island nation of Tonga.The Australian victim was a woman swimming with her dog and the attack may have been provoked by fishermen throwing bloody fish parts into the water as they cleaned their catch nearby, Burgess said.The Brazilian fatality was a man surfing off the northeast coast. The Tongan death involved a 24-year-old female swimmer who was an American Peace Corps volunteer. The deadly attack off Reunion Island was on a 34-year-old man surfing in an area where swimming is forbidden, Burgess said.Including the four fatalities, the researchers verified seven attacks in Australia, four in South Africa, three in Brazil, two in the Bahamas and one each in Fiji, Guam, Mexico, New Zealand, Puerto Rico, Reunion Island, Spain and Tonga.The researchers counted only attacks they considered unprovoked by the victims, excluding those in research pens or aquaria and those occurring when fishermen caught sharks.