Jamanji dropped only 10% this weekend making it have the seventh largest 8th weekend of all time
I'm guessing it held so well because it was a good alternative to 50 Shades, next weekend will be a good test against Black Panther. More theaters are being taken away from Jumanji as well.
Most recent estimates put it at ~882 million worldwide. Only 118 million to go. 1 billion hinges on Japan, but it'll get awfully close.