To those saying that growing inflation and population are balanced, somehow, by the fact that "people today have other options" and increasing piracy and whatnot... I say take a look at the OP again. The top of the list is *dominated* by movies from the 2000s, including such timeless treasures as Hancock and Sex and the City.
Why? Because we're living in the golden age of cinema? Because, like Avatar, each of those films "deserves" it? Nope! Because the population has grown, and the ticket price has gone up and up and up, and so any successful movie of today has a decent shot at that list.
In ten years, the list will be dominated by movies released from 2010-2020, and not because the films themselves will necessarily be any better--or have sold more tickets/been more popular--but because the ticket price will have gone up some more.