pension plans, in the absence of legislation limiting pension benefits and earnings that may be considered in calculating pension benefits. In addition, we provide medical and life insurance benefits to retirees and their eligible dependents through our postretirement plans, which, in general, are also unfunded obligations.

In 2005, we made required U.S. qualified plan contributions of $3 million and voluntary tax-deductible contributions in excess of minimum requirements of $49 million to our U.S. pension plans. In 2004, we made required U.S. qualified plan contributions of $29 million and voluntary tax-deductible contributions in excess of minimum requirements of $52 million to our U.S. pension plans. In the aggregate, the U.S. qualified pension plans are overfunded

on an accumulated benefit obligation measurement basis as of December 31, 2005 and 2004.

Outside the U.S., in general, we fund our defined benefit plans to the extent that tax or other incentives exist and we have accrued liabilities on our consolidated balance sheets to reflect those plans that are not fully funded.

The accounting for benefit plans is highly dependent on actuarial estimates, assumptions and calculations which result from a complex series of judgments about future events and uncertainties (see “Estimates and Assumptions” above). The assumptions and actuarial estimates required to estimate the employee benefit obligations for the defined benefit and postretirement plans, include discount rate; expected salary increases; certain employee- related factors, such as turnover, retirement age and mortality (life expectancy); expected return on assets; and healthcare cost trend rates. Our assumptions reflect our historical experiences and our best judgment regarding future expectations that have been deemed reasonable by management. The judgments made in determining the costs of our benefit plans can materially impact our results of operations. As such, we often obtain assistance from actuarial experts to aid in developing reasonable assumptions and cost estimates.

Our assumption for the expected long-term rate of return-on- assets in our U.S. pension plans, which determines net periodic benefit cost, is 9% for 2006 and 2005. The assumption for the expected return-on-assets for our U.S. and international plans reflects our actual historical return experience and our long-term assessment of forward-looking return expectations by asset classes, which is used to develop a weighted-average expected return based on the implementation of our targeted asset allocation in our respective plans. The expected return for our U.S. plans and the majority of our international plans is applied to the fair market value of plan assets at each year end. For our international plans that use a market-related value of plan assets to calculate net periodic pension cost, shifting to fair market value of plan assets would serve to decrease our 2006 international pension plans’ pre-tax expense by approximately $29 million. As a sensitivity measure, holding all other assumptions constant, the effect of a one-percentage-point decline in the return-on- assets assumption would be an increase