in 2013 what was the percent of the net periodic benefit cost attributable to the us
13 . pension and other postretirement benefit plans the company has defined benefit pension plans covering eligible employees in the united states and in certain of its international subsidiaries . as a result of plan design changes approved in 2011 , beginning on january 1 , 2013 , active participants in merck 2019s primary u.s . defined benefit pension plans are accruing pension benefits using new cash balance formulas based on age , service , pay and interest . however , during a transition period from january 1 , 2013 through december 31 , 2019 , participants will earn the greater of the benefit as calculated under the employee 2019s legacy final average pay formula or their new cash balance formula . for all years of service after december 31 , 2019 , participants will earn future benefits under only the cash balance formula . in addition , the company provides medical benefits , principally to its eligible u.s . retirees and their dependents , through its other postretirement benefit plans . the company uses december 31 as the year-end measurement date for all of its pension plans and other postretirement benefit plans . net periodic benefit cost the net periodic benefit cost for pension and other postretirement benefit plans consisted of the following components: .

|  | Pension Benefits | Other Postretirement Benefits |
| :--- | :--- | :--- |
| Years Ended December 31 | 2013 | 2012 | 2011 | 2013 | 2012 | 2011 |
| Service cost | $682 | $555 | $619 | $102 | $82 | $110 |
| Interest cost | 665 | 661 | 718 | 107 | 121 | 141 |
| Expected return on plan assets | (1,097) | (970) | (972) | (126) | (136) | (142) |
| Net amortization | 336 | 185 | 201 | (50) | (35) | (17) |
| Termination benefits | 58 | 27 | 59 | 50 | 18 | 29 |
| Curtailments | (23) | (10) | (86) | (11) | (7) | 1 |
| Settlements | 23 | 18 | 4 | — | — | — |
| Net periodic benefit cost | $644 | $466 | $543 | $72 | $43 | $122 |

the increase in net periodic benefit cost for pension and other postretirement benefit plans in 2013 as compared with 2012 is largely attributable to a change in the discount rate . the net periodic benefit cost attributable to u.s . pension plans included in the above table was $ 348 million in 2013 , $ 268 million in 2012 and $ 406 million in in connection with restructuring actions ( see note 3 ) , termination charges were recorded in 2013 , 2012 and 2011 on pension and other postretirement benefit plans related to expanded eligibility for certain employees exiting merck . also , in connection with these restructuring activities , curtailments were recorded in 2013 , 2012 and 2011 on pension and other postretirement benefit plans . in addition , settlements were recorded in 2013 , 2012 and 2011 on certain domestic and international pension plans . table of contents .

percent_us = 466 / 644
answer = percent_us * 100