of approximately $1.9 billion during 2014.

Discount Rate Used to Measure Plan Obligations

The weighted-average discount rate used to measure the plan obligations for our U.S. defined benefit plans is determined at least annually and evaluated and modified, as required, to reflect the prevailing market rate of a portfolio of high-quality fixed income investments, rated AA/ Aa or better, that reflect the rates at which the pension benefits could be effectively settled. The discount rate used to measure the plan obligations for our international plans is determined at least annually by reference to investment grade corporate bonds, rated AA/Aa or better, including, when there are sufficient data, a yield-curve approach. These discount rate determinations are made in consideration of local requirements.

The measurement of the plan obligations at the end of the year will affect the amount of service cost, interest cost and amortization expense reflected in our net periodic benefit costs in the following year.

The following table illustrates the sensitivity of net periodic benefit costs and benefit obligations to a 10 basis point decline in our assumption for the discount rate, holding all other assumptions constant (in millions, pre-tax):

                     Change

2015 Net Periodic 2014 Benefit Benefit Costs Obligations

Increase Increase $36 $480

    Assumption

 Discount rate 10 basis point decline

        The change in the discount rates used in measuring our plan obligations as of December 31, 2014 resulted in an increase in the measurement of our aggregate plan obligations by approximately $4.3 billion.

Contingencies

For a discussion about income tax contingencies, see Notes to Consolidated Financial Statements—Note 5D. Tax Matters: Tax Contingencies.

For a discussion about legal and environmental contingencies, guarantees and indemnifications, see Notes to Consolidated Financial Statements—Note 17. Commitments and Contingencies.

ANALYSIS OF THE CONSOLIDATED STATEMENTS OF INCOME

Revenues—Overview

 Total revenues were $49.6 billion in 2014, a decrease of 4% compared to 2013, which reflects an operational decrease of $1.1 billion, or 2%, and unfavorable foreign exchange of $912 million, or 2%, in 2014 compared to 2013. The operational decrease was primarily the result of:

• the expiration of the co-promotion term of the collaboration agreement for Enbrel in the U.S. and Canada (approximately $1.4 billion);

• the loss of exclusivity and subsequent multi-source generic competition for Detrol LA, Celebrex and Geodon in the U.S., Viagra in most major European markets, and Aricept and Lyrica in Canada (aggregate decline of approximately $937 million) and certain other products (approximately $300 million);

• the continued erosion of branded Lipitor in the U.S. and most other developed markets due to generic competition and the operational decline of certain products, including Norvasc, Effexor, atorvastatin, Metaxalone, Zosyn/Tazocin, Ziprasidone, Genotropin, Tygacil, Centrum, Advil and Vfend (approximately $938 million); and

• the ongoing termination of the Spiriva collaboration in certain countries (approximately $490