to aircraft fuel expense and fuel hedge margin for 2011 based on the impact of our open fuel hedge contracts at January 31, 2011, assuming the following per barrel prices of crude oil:  



Interest Rate Risk  

     Our exposure to market risk from adverse changes in interest rates is primarily associated with our long-term debt obligations. Market risk associated with our fixed and variable rate long-term debt relates to the potential reduction in fair value and negative impact to future earnings, respectively, from an increase in interest rates. At December 31, 2010, we had $8.6 billion of fixed-rate long-term debt and $6.8 billion of variable-rate long-term debt. An increase of 100 basis points in average annual interest rates would have decreased the estimated fair value of our fixed-rate long-term debt by $320 million at December 31, 2010 and would have increased annual interest expense on our variable-rate longterm debt by $55 million, inclusive of the impact of our interest rate hedge instruments.  

Foreign Currency Exchange Risk  

     Our results of operations may be impacted by foreign exchange rate fluctuations on the U.S. dollar value of foreign currency-denominated operating revenue and expense. Our largest exposures come from the Japanese yen and Canadian dollar. To manage exchange rate risk, we attempt to execute both our international revenue and expense transactions in the same foreign currency to the extent practicable. Changes in foreign currency exchange rates are not material to our results of operations.