26. Expenses by nature

NoteFor the period
from 1 January 2014
to 31 December 2014
from 1 January 2013
to 31 December 2013
Depreciation of property, plant and equipment and amortisation
of intangible assets
6.7 1 635 1 580
Employee benefits expenses 27 4 704 4 702
Materials and energy 7 607 7 899
External services 1 813 2 280
Taxes and charges 34 2 008 2 360
including the minerals extraction tax 34.1 1 520 1 856
Advertising costs and representation expenses 77 65
Property and personal insurance 31 33
Research and development costs not capitalised in intangible assets 9 8
Other costs, of which: 229 377
Impairment losses on property, plant and equipment,
intangible assets
6.7 43 257
Impairment losses on goodwill 7 25 27
Write-down of inventories 89 15
Allowance for impairment of receivables 32.2.5 3 10
Reversal of impairment of property, plant and equipment,
intangible assets
6 ( 5) ( 36)
Reversal of write-down of inventories ( 38) ( 3)
Reversal of allowance for impairment of receivables 32.2.5 ( 3) ( 1)
Losses from the disposal of financial instruments 31.3 7 9
Other operating costs 108 99
Total expenses by nature 18 113 19 304
Cost of merchandise and materials sold (+) 534 973
Change in inventories of finished goods and work in progress (+/-) 5 546
Cost of manufacturing products for internal use (-)* (1 513) (1 307)
Total cost of sales, selling costs and administrative expenses 17 139 19 516
of which:
Cost of sales 15 751 18 101
Selling costs 390 426
Administrative expenses 998 989

* A significant item in the adjustment is the capitalised stripping costs of surface mines in the KGHM INTERNATIONAL LTD. Group, details presented in note 3.3.