Is a Barred Rock an excellent or good layer?

[farmmanjim]

I have 17 barred rocks now 18 months old. I find no illness siggns. They get good quality pellets. They always have scratch. They get fresh veggies and grass. Their houses are clean. Their pen is 2000 square feet and safe. They also get out on my 7 acres, several afternoons a week. My egg count has gone from 15 a day to about 7 or 8 every day. Some days I still get 10 or 12 but normal is about 8. This is end of August. They still get plenty of light, always have fresh water. None are molting or broody. I was expecting good layers. My Rhode island were consistent but first time I've tried barred rocks. Any thoughts?