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 2013 (1): service cost: 682
interest cost: 665
expected return on plan assets: -1097
net amortization: 336
termination benefits: 58
curtailments: -23
settlements: 23
net periodic benefit cost: 644
pension benefits 2012 (1): service cost: 555
interest cost: 661
expected return on plan assets: -970
net amortization: 185
termination benefits: 27
curtailments: -10
settlements: 18
net periodic benefit cost: 466
pension benefits 2011: service cost: 619
interest cost: 718
expected return on plan assets: -972
net amortization: 201
termination benefits: 59
curtailments: -86
settlements: 4
net periodic benefit cost: 543
pension benefits 2013 (2): service cost: 102
interest cost: 107
expected return on plan assets: -126
net amortization: -50
termination benefits: 50
curtailments: -11
settlements: 2014
net periodic benefit cost: 72
pension benefits 2012 (2): service cost: 82
interest cost: 121
expected return on plan assets: -136
net amortization: -35
termination benefits: 18
curtailments: -7
settlements: 2014
net periodic benefit cost: 43
2011: service cost: 110
interest cost: 141
expected return on plan assets: -142
net amortization: -17
termination benefits: 29
curtailments: 1
settlements: 2014
net periodic benefit cost: 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 .

Questions:
what was the service cost in 2013?
and what was it in 2012?
how much, then, did the 2013 amount represent in relation to this 2012 one?
and what is this value excluding the part equivalent to the 2012 amount?
and between those two years, what was the variation in the net amortization?
what is this variation as a percentage of that net amortization in 2012?

Answers:
682
555
1.2288
22.88%
151
81.6%