In May 2003, I was in Zimbawe for a couple of days. In 2 days the black market rate for $1US went from 1,200ZW to 1,600ZW.
In September 2007, official rate was US$1 for ZW$30,000 while black market was around ZW$600,000
On April 4, 2008, Zimbawe issued a new ZW$50,000,000 note worth approximately US$1 in the black market.
I kept as a souvenir a ZW$500 note from 2003. So now it’s worth $US0.00001
And this is with the US dollar worth not much. (0.637€)