Recently my hens' egg production is slowing down drastically. I have 12 plymouth rocks and I used to get about ten eggs a day. Now I'm lucky if I get half that much. I have a 95 watt light set up to go from 1 AM to 8 AM. The sun rises around 7:30 and sets around 5:30 which is almost 16 hours of light. As far as I know they aren't egg-eaters so what is the problem?