11. Property, plant and equipment (in millions of euros)LandBuildingOther fixed installationsRolling stockPartsMachinery & equipmentAssets under constructionTotalComposition per 1 January, 2015 Cost1295571705,966966044057,927Cumulative depreciation and impairments 312561293,80066488- 4,770Carrying amount as at 1 January, 201598301412,166301164053,157 Changes in 2015 Additions 463463Capitalisations21337155152-351-1Depreciation-1-21-8-224-3-29- -286Exchage rate differences- 1- 1- - - 2Divestments-2- - 1- -4- -5Impairments- - -1- - -1- -2Reversal impairments- - - 2- - - 2Other changes- - -72- -26-3-34Total changes-1113-9-63-2-8109139 Composition per 31 December 2015 Cost1256881445,860975265147,954Cumulative depreciation and impairment 282741123,75769418- 4,658Carrying amount as at 31 December 201597414322,103281085143,296(in millions of euros)LandBuildingOther fixed installationsRolling stockPartsMachinery & equipmentAssets under constructionTotalChanges in 2016 Additions 704704Capitalisations47707406158-54247Depreciation-2-25-7-206-3-27- -270Exchange rate differences- -1- -2- -3- -6Divestments-4-1-3-6- -2- -16Impairments- -24- - - - - -24Reversal impairments- - - - - - - - Other changes- -31-62- -9-4-77Total changes4116-2130-217158358 Composition per 31 December 2016 Cost1687501446,139975296728,499Cumulative depreciation and impairment 303201143,90671404- 4,845Carrying amount as at 31 December 2016138430302,233261256723,654The other changes in 2016 are mainly due to the transfer of tangible assets to assets held for sale (note 19) of € 76 million. Works and equipment under construction mainly consist of investments in trains and buildings.Part of the rolling stock included as at the balance sheet date is part of the cross-border lease transactions that were concluded in the past. The book value of rolling stock financed by cross-border leases was €81 million at year-end 2016 (2015: €112 million).For Eurofima loans that are not part of the cross-border lease finance arrangements, collateral has been provided in the form of pledges on rolling stock (see note 30). The book value for this is €10 million (2015: € 274 million). The decline of the pledge is due to the decrease of the Eurofima loans.Impairment and reversalsAs a result of developments in the lease portfolio of a station complex in the Netherlands, a review has been performed of the recoverable amount of this complex. The recoverable amount is set at € 78 million. This has resulted in an impairment loss of € 24 million.The calculations that give rise to the impairments and their reversals are based on a weighted average post-tax discount rate that is between 5.5% and 7% (2015: between 5.5% and 7%).