How many sets of books are there in total for celebrating the remaining years?

There were some contradictions and uncertainties about the number of books in the complete set of " Celebrating Years ". Some documents mentioned that there were 12 books in total, while others mentioned that there were 15 books in total. Therefore, it is impossible to determine how many books there are in the entire set of "Celebrating Years".

There are a total of 12 sets of books in the year of celebration.

There are a total of 12 sets of books in the year of celebration.

There are a total of 12 sets of books in the year of celebration.

There are a total of 12 sets of books in the year of celebration.

There are a total of 12 sets of books in the year of celebration.

There are a total of 12 sets of books in the year of celebration.

There are a total of 12 sets of books in the year of celebration.

There are a total of 12 sets of books in the year of celebration.

There are a total of 12 sets of books in the year of celebration.

There are a total of 12 sets of books in the year of celebration.