$1 in Jan 2005 is only 1.69 today, not $4 because the velocity of money has decreased dramatically as it has pooled towards the top of the income/wealth spectrum where it doesn't get spent or productively invested.
Bulk of it is that, but some of it is that larger economy needs more money to run. So while there was 4 food money supply increase the legitimate demand also increased somewhat. Exact numbers might be hard to pinpoint because we tend to measure economy in dollars but still it wouldn't be $4 even if the rich didn't get disproportionately wealthy from this supply.