Check out #5 from National Geographic:
North Carolina’s “Perfect Storm” for Shark Attacks
However, in Australia, where it is now winter, there have been two attacks in two days:
Lennox Head shark attack: Surfer knocked off board day after bodyboarder mauled at Ballina
Could it be that there is now a world-wide overpopulation of sharks in search of shrinking food sources, or that it's summer in the USA and, as I know from experience, reporters "pre-write" shark attack stories for the time of year when up to half the newsroom is on vacation? Nah.