(The Hill) — Almost 1,500 school book bans were put into place around the U.S. in the first half of the current academic year, according to PEN America.

An analysis from the group released Thursday found 1,477 book bans implemented in the first half of the 2022-2023 school year, affecting 874 unique books. The six months prior, from January 2022 to June, there were 1,149 instances of book bans found by the free speech organization. 

While PEN America put together a comprehensive report, it says the number of book bans is “unquestionably much higher” than what it was able to gather from public information. 

It distinguished among four different types of book bans: banned in libraries and classrooms, banned in libraries, banned in classrooms and banned pending investigation. 

Banned pending investigation was the most popular category for the first half of the current school year, making up 52% of the book bans, the organization found. 

“Though timelines vary across districts, investigations can be time-consuming, resulting in bans on particular titles that last months at a time. These restrictions are recorded as bans because they 1) remove access to books, even if temporary, and 2) are counter to procedural best practices for book challenges from the American Library Association (ALA) and the National Coalition Against Censorship (NCAC),” PEN America said in a statement. 

Among the almost 900 unique books taken off the shelves, 44% have themes of violence, 38% involve health and well-being, 30% have themes of death and grief, 30% discuss racism and have characters of color, 26% include LGBTQ themes and characters, 24% had to do with sexual experiences between characters and 17% dealt with teen pregnancy and abortion. 

Much of the discussion around banning books in the U.S. has to do with the perceived appropriateness of books for certain age groups. Some Republicans have asserted there are books with pornographic material on the shelves in schools. 

“Over the last year, however, terminology such as ‘obscene,’ ‘pornographic,’ ‘harmful to minors,’ and ‘sexually explicit’ is being utilized to restrict a range of content, including books on LGBTQ+ experiences, stories that include any sexual references, sex education materials, books that include portrayals of death or abuse, and art books,” PEN America said. 

The report found the states with the most book bans include Texas, Florida, Missouri, Utah and South Carolina, which have all implemented laws that put some restrictions on the type of material allowed in the classroom. 

Much of the legislation around what books can be on the shelves in schools is vaguely worded, causing librarians and teachers to preemptively take books off the shelves for fear of political backlash.

“The heavy-handed tactics of state legislators are mandating book bans, plain and simple,” said Suzanne Nossel, CEO of PEN America. “Some politicians like Florida Governor Ron DeSantis have tried to dismiss the rise in book bans as a ‘hoax.’ But their constituents and supporters are not fooled. The numbers don’t lie, and reveal a relentless crusade to constrict children’s freedom to read.” 

The top five books that have been banned in the first half of the school year include “Gender Queer: A Memoir,” “Flamer,” “Tricks,” “The Handmaid’s Tale: The Graphic Novel” and “Crank.”