Please answer the given financial question based on the context.
Context: 14 . accounting for certain long-lived assets eog reviews its proved oil and gas properties for impairment purposes by comparing the expected undiscounted future cash flows at a depreciation , depletion and amortization group level to the unamortized capitalized cost of the asset . the carrying rr values for assets determined to be impaired were adjusted to estimated fair value using the income approach described in the fair value measurement topic of the asc . in certain instances , eog utilizes accepted offers from third-party purchasers as the basis for determining fair value . during 2017 , proved oil and gas properties with a carrying amount of $ 370 million were written down to their fair value of $ 146 million , resulting in pretax impairment charges of $ 224 million . during 2016 , proved oil and gas properties with a carrying rr amount of $ 643 million were written down to their fair value of $ 527 million , resulting in pretax impairment charges of $ 116 million . impairments in 2017 , 2016 and 2015 included domestic legacy natural gas assets . amortization and impairments of unproved oil and gas property costs , including amortization of capitalized interest , were $ 211 million , $ 291 million and $ 288 million during 2017 , 2016 and 2015 , respectively . 15 . asset retirement obligations the following table presents the reconciliation of the beginning and ending aggregate carrying amounts of short-term and long-term legal obligations associated with the retirement of property , plant and equipment for the years ended december 31 , 2017 and 2016 ( in thousands ) : .
||2017|2016|
|carrying amount at beginning of period|$ 912926|$ 811554|
|liabilities incurred ( 1 )|54764|212739|
|liabilities settled ( 2 )|-61871 ( 61871 )|-94800 ( 94800 )|
|accretion|34708|32306|
|revisions|-9818 ( 9818 )|-38286 ( 38286 )|
|foreign currency translations|16139|-10587 ( 10587 )|
|carrying amount at end of period|$ 946848|$ 912926|
|current portion|$ 19259|$ 18516|
|noncurrent portion|$ 927589|$ 894410|
( 1 ) includes $ 164 million in 2016 related to yates transaction ( see note 17 ) . ( 2 ) includes settlements related to asset sales . the current and noncurrent portions of eog's asset retirement obligations are included in current liabilities - other and other liabilities , respectively , on the consolidated balance sheets. .
Question: considering the years 2016 and 2017 , what is the average current portion?


Answer: The answer is:18887.5