Our egg count has gone waaaaay down, too, and our one green egg layer hasn't dropped one in a couple of weeks now. I'm curious as well. Thanks for putting this question out there!
They've probably just stopped laying for the winter. I actually made a post about this a few days ago, and while I really really really want them to lay throughout the winter, I got a lot of responses that said it is best to let them have a break, since laying takes a huge toll on their bodies.
But be warned if you make them lay during the winter their long term egg laying life span will be shorter, so many of us just let nature run its course.
I agree on the taking-a-break part, but it is up to you if you want to add light or other thingsUp to you if you want to do that
How old are your birds, in weeks or months?