We have
10 volumes, but sometimes it takes a while for us to receive the following batch of work files. We now have the next two volumes, but because we got the data fairly recently, we already had the May slots filled. All I can say at this moment is that Vol.11 should come out shortly after that.
I recommend checking out the
Doujinshi Previews which updates at the end of each month to see what's coming up next.