My egg production is down also. I do not supplement their light except for a couple hours in the morning. Out of the last 4 days I've gotten 3 days of 5 eggs and 1 day of 8 eggs. I have 17 hens. I'm thinking some are moulting as there are lots of feathers in the coop. At least 5 EE's are not laying at all and I have 7 of them. My girls were born in March and April.
So odd you said that about your EE's-- I have 3× 1.5yos and 5x Hatched this past spring and in 2+weeks have seen no EE eggs... My 10 brown layers are laying albeit not well but 4-6 a day from the 2x 1.5yos and 8 spring hatches. I wonder why there is a difference? We also supplement a few hours of light in the morning but I let them out of the coop before I leave for work when it is still dark-- I wonder if most of them are spending those 2 hours or so in the run not getting the benefits of the light in the coop?