Bristol-Myers Squibb  Weighted-average actuarial assumptions used to determine net periodic benefit cost for the years ended December 31 were as follows:  The yield on high quality corporate bonds that matches the duration of the benefit obligations is used in determining the discount rate. The Citigroup Pension Discount curve is used in developing the discount rate for the U.S. plans.  Several factors are considered in developing the expected return on plan assets, including long-term historical returns and input from  external advisors. Individual asset class return forecasts were developed based upon market conditions, for example, price-earnings  levels and yields and long-term growth expectations. The expected long-term rate of return is the weighted-average of the target asset  allocation of each individual asset class. Historical long-term actual annualized returns for U.S. pension plans were as follows:  $^{ }$Pension and postretirement liabilities were increased by $459 million at December 31, 2012 with a corresponding charge to other  comprehensive income as a result of actuarial losses attributed to the benefit obligation ($731 million) partially offset by higher than  expected return on plan assets ($272 million). These actuarial losses resulted from prevailing equity and fixed income market  conditions and a reduction in interest rates in 2012.  The expected return on plan assets was determined using the expected rate of return and a calculated value of assets, referred to as the  “market-related value” which approximates the fair value of plan assets at December 31, 2012. Differences between the assumed and  actual returns are amortized to the market-related value on a straight-line basis over a three-year period.  Gains and losses have resulted from changes in actuarial assumptions (such as changes in the discount rate) and from differences  between assumed and actual experience (such as differences between actual and expected return on plan assets). These gains and  losses (except those differences being amortized to the market-related value) are only amortized to the extent they exceed 10% of the  higher of the market-related value or the projected benefit obligation for each respective plan. As a result, approximately $840 million  related to pension benefits is not expected to be amortized during 2013. The majority of the remaining actuarial losses are amortized  over the life expectancy of the plans’ participants for U.S. plans (30 years) and expected remaining service periods for most other  plans into cost of products sold, research and development, and marketing, selling and administrative expenses as appropriate.  Assumed healthcare cost trend rates at December 31 were as follows:  Assumed healthcare cost trend rates have an effect on the amounts reported for the healthcare plans. A one-percentage-point change  in assumed healthcare cost trend rates would have the following effects:  Pension Benefits Other Benefits 2012  2011 2010 2012 2011 2010 Discount rate 4.4 %  5.2 %  5.6 %  4.1 %  4.8 %  5.5 %  Expected long-term return on plan assets  8.2 8.3 8.3 8.8 8.8 8.8 Rate of compensation increase  2.3 %  2.4 %  3.7 %  2.0 %  2.0 %  3.5 %  2012 2011 2010 10 years 8.5 %  5.6 %  4.7 %  15 years  6.5 7.0 7.9 20 8.5 %  8.1 %  9.3 %  2012 2011 2010 Healthcare cost trend rate assumed for next year 6.8 %  7.4 %  7.9 %  Rate to which the cost trend rate is assumed to decline (the ultimate trend rate)  4.5 4.5 4.5 Year that the rate reaches the ultimate trend rate  2018  2018 2018 1-Percentage-  1-Percentage-  Dollars in Millions Point Increase  Point Decrease  Effect on total of service and interest cost $   1 $ (1) Effect on postretirement benefit obligation   25 (25) 60