I'm sorry, but I don't have any specific context or data to provide you with the number of books published. The number of books published each year varies greatly and depends on many factors such as time period, country, and type of book.
If you need this information for a specific context or time period, please provide more details so I can try to help you better. Otherwise, you may want to refer to reports from organizations like the International Publishers Association or research institutions that track global publishing statistics.