risen a third or so: increased in
value compared to the dollar by about 33%
banknotes: pieces of paper money
circulate: here, be used by people
transactions: business deals involving
buying or selling
supported: helped to keep it at
a high level
forgery: the crime of making and using false banknotes
to deceive people
speculators: speculators buy things
in the hope of selling them later at a profit
stashed: an informal word for hiding
something to keep it safe
oil wealth: financial resources
from the sale of oil
pushed up: made it rise higher