Furthermore, the fair value of derivative instruments fluctuates over time as a result of the effect of future interest rates, exchange rates and financial market volatility. These values must be analyzed in relation to the fair values of the underlying transactions and as part of our overall exposure to fluctuations in interest rates and foreign exchange rates. Since valuation is imprecise and variable, it is difficult to predict accurately the magnitude of the risk posed by our use of derivative financial instruments going forward and to state with certainty that we will not be negatively affected by our derivative financial positions.