I would guess our collective purchases of Dinar are 3 or 4 days worth of oil exports.
$55 (approx. oil) * 2 mbpd (oil exports per day) = 110,000,000 USD per day.
5 days = 550,000,000 USD - that half a billion in 5 days...
Of course its not quite as simple as this but you get the idea. We are a few drops in the bucket compared to others (such as Kuwait - 28 billion) who were owed billions.