There's more people than there has ever been before enjoying water sports. I can't even tell you whether the statistics show that the number of shark attacks are increasing, but my guess if they are it isn't because the shark numbers have dramatically increased, but more likely because more people are out on the ocean putting themselves at risk.
It's interesting people talk about saving human lives, so kill the sharks, but there's roughly 90 times more people dying from drowning than there is from shark attacks annually. Ironically if people just stayed out of the water we'd save a few people from shark attacks whilst saving a few hundred from drowning....