Equivalancy Jokes

An Asian gentleman walks into an American bank needing to exchange currency. Handing over 55 yen, he is told by the teller that the equivalancy in american dollars will be $96.00. completing his transaction, he smilingly leaves the bank. One week later he returns to again, exchange some cash. Giving the teller 55 yen, he is told that the equivalancy will be $91.00. "What you talk about!", he exclaims. "Last week I come in, 55 yen is $96.00 dollar and today it only $91.00, you trying to cheat me?". "No sir", the teller tried to explain, "..fluctuations..".