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: .

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years ended december 31 | pension benefits 2013 | pension benefits 2012 | pension benefits 2011 | pension benefits 2013 | pension benefits 2012 | 2011
----------|----------|----------|----------|----------|----------|----------
service cost | $ 682 | $ 555 | $ 619 | $ 102 | $ 82 | $ 110
interest cost | 665 | 661 | 718 | 107 | 121 | 141
expected return on plan assets | -1097 ( 1097 ) | -970 ( 970 ) | -972 ( 972 ) | -126 ( 126 ) | -136 ( 136 ) | -142 ( 142 )
net amortization | 336 | 185 | 201 | -50 ( 50 ) | -35 ( 35 ) | -17 ( 17 )
termination benefits | 58 | 27 | 59 | 50 | 18 | 29
curtailments | -23 ( 23 ) | -10 ( 10 ) | -86 ( 86 ) | -11 ( 11 ) | -7 ( 7 ) | 1
settlements | 23 | 18 | 4 | 2014 | 2014 | 2014
net periodic benefit cost | $ 644 | $ 466 | $ 543 | $ 72 | $ 43 | $ 122
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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 .

Question: considering the years 2012 and 2013 , what is the increase observed in the service cost?
Program: divide(682, 555), subtract(#0, const_1)
Answer: 0.22883