about 15% of all US issued notes and coins in circulation. ( according to the following two sources)
from the fed.
There was approximately $1.19 trillion in circulation as of May 15, 2013, of which $1.14 trillion was in Federal Reserve notes.
If you still think money exists as folding Green? , lets see what William Taylor Colleridge had to say about this?
this from 27th April 1823.
The national debt has, in fact, made more men rich than have a right to be so, or, rather, any ultimate power, in case of a struggle, of actualizing their riches. It is, in effect, like an ordinary, where three hundred tickets have been distributed, but where there is, in truth, room only for one hundred. So long as you can amuse the company with any thing else, or make them come in successively, all is well, and the whole three hundred fancy themselves sure of a dinner; but if any suspicion of a hoax should arise, and they were all to rush into the room at once, there would be two hundred without a potato for their money; and the table would be occupied by the landholders, who live on the spot.
So in a dash for Cash who gets to the front of the que first you or Apple and Mr Cook? Lots of Cypriots might give you an answer that is cause for concern.