[LoonyBalloony]

Seems like society is doing everything it can to keep this trend going: http://i.imgur.com/Uc6kX8G.jpg

[mapmap]

Is this correlated to the gold standard ending in the early seventies?

[droidist2]

I would guess it's correlated to the rise of other manufacturing competitors like Japan, Taiwan, and later China. After World War II the US had an easier time as much of Asia and Europe's capacity was destroyed.