Are there fewer reviewers nowadays?

Apologies if this has been brought up before and I just couldn't find it, but are there fewer janitors around these days? I remember that at one point every upload would be reviewed by 10, but lately it seems like 7 is the norm, with some posts, like post #3738638, seeing as few as 6. I feel like this has coincided with suddenly seeing posts that I would normally think were sure to pass just dropping out. Are we just short on janitors, or am I missing something else?

One cause is that some approvers seem to never choose any of the disapprove options on posts which in turn results in them not counting in the number of approvers that have reviewed the image, giving the illusion fever approvers have seen it.

I've seen several people bring this up lately. I just added three new approvers this week to try to bring activity levels back up to normal. I'm waiting to see if that will be enough. I also raised the approver activity requirements, so that approvers who aren't active enough will lose their privileges and be replaced by someone else.