I’ve done a very rough division of publishers into big, medium and small. Big is easy to define: the parent company is some sort of huge corporate entity doing hug corporate entity things. Medium? Well don’t ask me for a good definition but the sort-of-company-that-gets-bought-out by a huge corporate entity. Basically, I lumped in all sorts of publishers that had many significant properties and what looks like a corporate structure etc. “Small” is an even worse crime against taxonomy and is basically everybody else from Castalia House to LMBPN to self-published works.
Here’s how the awards split by publisher size, winner/finalist and gender (as marked by pronouns) for all printed categories (books and comics).
On pronouns, I don’t think there is a finalist who uses pronouns other than he/him or she/her but I may be wrong. The totals don’t add up to 100% because there are a few finalist only listed as “various” which I didn’t include.
Generally, gender representation is more equitable with the bigger publishers and worse with the medium sized publishers.
The change in character of the award is mapped out in this table.
Aside from 2017, the percentages for “medium” have been fairly stable. The growth in works from the big publishers has been at the expense of the small publishers/self-published works.
Here is how those percentages shift when just looking at the winners.