3. Operating expenses/(income)

Raw materials and consumables69,52946,30569,52946,305
Other external charges78,52951,92378,52951,923
Fair value movement in contingent consideration (note 29)9991,3149991,314
Staff costs (note 4)85,83353,66885,83353,668
Depreciation (note 13)10,3067,99310,3067,993
Amortisation of acquisition-related intangible assets (note 15)13,1406,78513,1406,785
Amortisation of other intangible assets (note 15)333178333178
Loss/(profit) on disposal of property, plant and equipment6951669516
Exchange losses441282441282
Increase in inventory of finished goods and work in progress2,1479,5112,1479,511
Operating expenses include the following:
Operating lease rentals1,6461,547
Research and development4,4968,392
Trade receivables impairment (note 18)837215
Property, plant and equipment repairs and maintenance10,3165,997
Cost of inventories recognised as an expense69,52946,305
Change in the fair value of derivative instruments outstanding at year end and classified as fair value through profit and loss374376
Services provided by the Company's auditors
Fees payable to the Company's auditors for the audit of the parent Company and consolidated accounts14778
Fees payable to the Company's auditors and its associates for other services:
– The audit of accounts of the Company's subsidiaries pursuant to legislation241372
– Audit-related assurance services41
– Tax compliance services12
– Tax advisory services3069
– Corporate finance services604
– Other assurance services1229

Tax advisory and other assurance services provided during the year relate to services provided by PricewaterhouseCoopers.

Corporate finance services in the prior year related to fees for due diligence and reporting accountant work performed in relation to the acquisition of Aesica.

No government grants were received in the year (FY2015: £15,000). The Group also realised an R&D tax credit of £2.4m (FY2015: £0.9m) which was recognised through operating profit. Research and development costs disclosed above are net of R&D tax credit.