More than 4,000 book titles were threatened last year in public libraries, schools and universities across the country — the largest number challenged since the American Library Association (ALA) began recording censorship data about 20 years ago.

National Library Week kicked off Monday with the release of ALA’s list of most challenged books in 2023. In all, 4,240 titles – up from about 2,500 in 2022, or a 65 percent increase – were challenged or banned last year.

Eight of the ten most banned books last year, including the top five, were challenged in part for containing LGBTQIA+ representation. Opponents of these novels also claimed they were sexually explicit.

The top five challenged books included: “Gender Queer,” by Maia Kobabe; “All Boys Aren’t Blue,” by George M. Johnson; “This Book is Gay,” by Juno Dawson; “The Perks of Being a Wallflower,” by Stephen Chbosky; and “Flamer,” by Mike Curato.

“These are books that contain the ideas, the opinions, and the voices that censors want to silence – stories by and about LGBTQ+ persons and people of color,” ALA Office for Intellectual Freedom Director Deborah Caldwell-Stone said in a statement. “Each challenge, each demand to censor these books is an attack on our freedom to read, our right to live the life we choose and an attack on libraries as community institutions that reflect the rich diversity of our nation.”

The last few years have been tumultuous for libraries, with 1,247 censorship attempts reported in 2023, according to the ALA. These challenges impact library books, programs and displays and deny students and patrons the opportunity to learn about important issues and underrepresented groups, librarians said.

Books depicting the lived experiences of LGBTQIA+ and BIPOC people, particularly “difficult topics” like violence and racism, made up 47 percent of all targeted censorship attempts.

“These are not ordinary times,” said ALA President Emily Drabinski in a statement. “The unprecedented wave of organized censorship intensifies, particularly in our public libraries. Adverse legislation that would undermine librarian agency and authority is getting a hearing in legislatures across the country.”

Florida and Texas lead the country on book bans, but incidents of censorship have been recorded in 41 states. Seventeen states reported threats on more than 100 titles, including Connecticut, Florida, Ohio, Pennsylvania and Tennessee.

According to a report by PEN America, these efforts have inspired “copycat bans,” which is when a district will restrict access to a book seemingly because it was removed elsewhere. The report also noted that some authors of banned books experience what’s known as a “scarlet letter” effect, with more of their works targeted after the first ban.

Although censorship reports decreased, the ALA found that the number of unique book challenges increased by more than 30 percent due to groups threatening several titles at once. The majority of these books were included in lists of books deemed inappropriate for readers that were circulated by groups like Moms for Liberty and No Left Turn in Education.

The previous record for highest book challenges was in 2022. Between 2001 through 2020, the average number of titles targeted for censorship was 273. Within those two decades, a total of 3,637 novels were challenged, which is about 600 fewer books than those threatened last year.

The theme for this year’s Banned Books Week is “Freed Between the Lines” to celebrate the knowledge gained from reading. The ALA event will take place Sept. 22-28.