Anecdotal since everyone normally has a joke about what currency to take abroad
Angola kwanza used to be around 98 to the $ but has weakened to around 168 on the official Bank Rate just now
Rate on the street was around 350 November, 450 in February and now 600 Kwanza to $
means beers are cheap, and mega expensive Luanda aint so bad
Crazy that you can get 3.5 times an exchange rate
Banks don't have/or are not releasing currency - so anyone travelling abroad need to negotiate their own rate, and less overseas staff visiting so less overseas currency around as well