User blog comment:B214/Question and Answers 2/@comment-202.152.195.64-20140605084653/@comment-16281343-20140605163303

Found some other things about this.

DxD has fallen off of the top 20 and is now ranked 28, but if you view the release date of the novels ranked higher than DxD, they were released way before DxD.

So, the sales is still good. Here's the list, if anyone's interested.