We have 6 ladies (1.5 years old) who have consistently been providing us with 5-6 eggs/day for close to a year. Within the last 3 weeks, they are down to just 1-2 eggs/day. There has been no change in nutrition or any other routine. I understand there is less daylight, but even last winter we consistently were getting 3-4 eggs/day. Thoughts on why the decrease in production?