Jumbo Eggs

Does anyone know anything about chickens?  Specifically their eggs? 

A while back I was doing some baking and Charles got all the particulars that I needed for those dishes.

He came home with 2 dozen jumbo eggs.  They were perfectly fine and the recipes worked well.   The odd thing was that 10 out of 24 were double yolks.

In all my years I have never encountered a double yolk in large eggs.  I think it may be more than a coincidence  that there were so many in the jumbo eggs.

Any thoughts y'all?