"The list shows the wide range of books that can get people rattled and touch upon their deepest fears and antagonisms," said Barbara Jones, who directs the library association's Office for Intellectual Freedom.
The office defines a challenge as a "formal, written complaint filed with a library or school requesting that a book or other material be restricted or removed because of its content or appropriateness." The office received 307 challenges last year, down from 464 in 2012 and far below the levels of the 1980s and '90s.
Exact numbers, including how many books were actually pulled, are hard to calculate. The association has long believed that for every complaint registered, four to five go unreported by libraries and that some librarians may restrict access in anticipation of objections. The list is based on press accounts and reports from librarians, teachers and "concerned individuals."
"The number is low this year," Jones said. "We'd like to think it's because people finally understand that pulling a book from their shelves isn't going to solve the problem they're worried about it. But it could be an anomaly."
Many of the books are cited for the very actions and attitudes they were trying to criticize, whether "The Bluest Eye" for violence or Alexie's novel for racism. It's a long tradition, Jones noted, dating back at least to the accusations of racism made against Mark Twain's satirical "The Adventures of Huckleberry Finn."
"People focus on a word, or a handful of words, and often lift them out of the context of the books," Jones said.
The list often reflects what's popular among kids and young adults at the time. Over the past decade, the "Harry Potter" books and the "Twilight" series have appeared in the top 10, and Jones thought that the new report would include Veronica Roth's "Divergent" books.
"We might be a bit behind on that trend," Jones said. "But as far as next year, yeah, we're waiting."