Once again, it was all about The Avengers at the box office, as three new releases failed to even approach the Marvel superhero blockbuster’s third-weekend gross of $55.1 million, according to studio estimates. The movie dropped 47 percent — an admirable hold for a picture that’s putting up such huge numbers. By the end of Sunday, The Avengers will have made an estimated $457.1 million domestically, passing $450 million in a record 17 days. (The previous record holder, The Dark Knight, reached that milestone in 27 days.) Meanwhile, The Avengers also passed Pirates of the Caribbean: Dead Man’s Chest to become Disney’s biggest movie ever both domestically and worldwide. It now sits in fourth place on the all-time worldwide chart, behind only Avatar, Titanic, and Harry Potter and the Deathly Hallows — Part 2.