Countries that don't use a national currency are not normally listed on a foreign exchange rate chart, as shown by Trading Economics' list of countries with the respective exchanges rates for major markets. An example of one not listed is Ecuador, which uses the United States dollar as its currency.
A country's exchange rate fluctuates because of many economic factors and reflects its buying power in the world market. Nations with lower inflation rates typically have a higher currency value, while those with high inflation rates risk the devaluation of a currency. One cause of overinflation is when the market is flooded with new currency to pay off debt.