Book sales per genre?

A discussion elsewhere got me looking for something that's proved harder to find than I thought it'd be (or maybe I just overestimate my google fu), namely how many books are sold per genre. The data I've found divide books into a handful of extremely wide categories - e.g. Children's Fiction, Adult Non-Fiction - but I'd like to find something broken down to somewhat narrower genres, like Fantasy, Romance, History, etc.

Anyone know someplace where such can be found? For the whole world or for some particular country or region.

Part of the problem is going to be defining the genres. Is a particular book fantasy, science fiction or romance? Are you going to differentiate between thrillers and cozy mysteries?

Do you want the book sales to include used books? Are you going to include self-published books, and if so, how are you going to get the figures?

Genre assignment is not an exact science, of course, but right now I'd be happy with any classification assuming it's reasonably coherent and at approximately the right level.

Ideally all book sales ought be included, but data only including conventionally published new books would be far better than nothing.

I don't know which part of the world you live in but in the UK I would try the Booksellers Association, they publish a monthly magazine called The Bookseller and when I used to use it in the 80s/90s I have a dim memory of stats being published at the end of the year.

I live in Sweden. I did find some data from the Swedish Publichers' Association, but their list of genres is a bit more high-level than I was looking for:

Literary fiction
Crime, mystery, and thrillers
Humanities
Popular non-fiction
Non-fiction
Food and drink
Children's and young adult
Foreign literary fiction
Foreign non-fiction
Foreign children's and young adult

(My translations, not necessarily entirely precise - in particular "literary fiction" is only a rough equivalent of skönlitteratur - but if it strikes you as unclear where many books would go I've perserved that feature of the original. "Foreign" seems to mean in another language than Swedish.)

From the UK Booksellers' Association I find this, but it uses even coarser categories:

Adult Fiction
Adult Non-Fiction: Trade
Adult Non-Fiction: Specialist
Children's, Young Adult, & Educational

The original question that got me looking was whether people read more fantasy books than history ones.

If you mean non-fiction history, the answer is definitely going to be yes. But historical fiction would be harder to say. Especially since 'historical fiction' would not generally be distinguished as its own category in statistics.

>7 Cecrow: If you mean non-fiction history, the answer is definitely going to be yes.

Yes, I mean non-fiction history, and yes, I expect it to be less popular than fantasy - but my interlocutor didn't, so I started looking for data.