> The rest of the decline is (in my evaluation) best explained with the increase in average age of the 18-64 year old demographic. I wondered about this before

> The rest of the decline is (in my evaluation) best explained with the increase in average age of the 18-64 year old demographic. I wondered about this before reading the article, but there's a chart in the article comparing narrow ~10 year age ranges to their past levels, and the decline is persistent in each group, so I don't think it can be explained by the overall population being older.