Over the years, OEW has come down due to better materials, etc. But at least as much weight has come out of the fuel carried. A few percent per year over the decades; This is at least as significant as the structure weight!
I left fuel out of this one precisely to see if structural weight has decreased proportionally, to see if newer aircraft are lighter per passenger than older ones. It remains to be seen....
I hope many people will reply with their aircraft's figures.....