We could count the 20th and 21st centuries as a few different currency regimes, in which case we have more than _one_ data point. But yeah, point taken

denlillaapan

For the most part these dominant currency regimes were all backed by gold and silver.

Have we had a dominant purely fiat regime since the dollar?  I think the answer is no(?)  If so, then we really only 

econ

The Disappointing Randomness of Currency Hegemony (FT, Brendan Greeley)

For the most part these dominant currency regimes were all backed by gold and silver.

Have we had a dominant purely fiat regime since the dollar?  I think the answer is no(?)  If so, then we really only *one* data point for the current situation.