Over the past 50 years, the movie ratings board has approved almost 30,000 movies. The vast majority—17,202, to be exact—received an R rating. The Motion Picture Association of America released the data Monday in a comprehensive report tied to their 50th anniversary. (h/t Hollywood Reporter)

The next-biggest grouping below R is PG (only 5,578), then PG-13 (which has slackened considerably in the past decade, with only 4,913 movies total in 50 years). In addition, 524 movies received an X, or NC-17, rating.

The year 2003 saw a record amount of R movies, with 645 gracing the big screen across 12 months. PG-13 movies came in second that year with just 186. Last year saw 307 R-rated movies, including horror hit Get Out and erotic thriller Fifty Shades Freed. The superhero category also saw Logan in 2017, which comes between two other notable R-rated comic-book pictures: Deadpool and Deadpool 2. 

As a class, R-rated movies generate less revenue than PG or PG-13 movies, and studios know in general what a movie will be rated when the read the script. Language, of course, is a major indicator of rating, as well as explicit depictions of sex and violence.

Recent years have seen R-rated movies generate a surprising amount of money. A horror resurgence has seen movies like Get Out and this year’s Halloween make major dollars, and prestige flicks like A Star Is Born do well when their stories are centered around universal ideas like romance. Those R-rated comic movies do pretty alright, too.

Among this year’s 20 highest-grossing movies so far, four are R rated: Deadpool 2 (no. 5), A Star Is Born (13), Halloween (17) and The Nun (19). Last year saw three grace the top 20 (It, Logan and Get Out), and 2016 saw just one (Deadpool).