Having never been to Jamaica I was going by your quote:
" Back when I first visited Negril, there were not even 1 million visitors total to Jamaica at the time, with Negril receiving a small percentage of those visitors. This year we surpassed 2 million overnight visitors for the first time. And it looks like Negril will have hosted about a half million of those visitors for the first time. In 2012, Negril hosted about 415,000 visitors. "

From 1 million to 2 million visiting Jamaica and Negril received 415,000 of the 2 million.