6. Other operating expenses
2017 2016
Rents/leases -13.9 -13.2
Losses on disposal of non-current assets -0.1 -0.2
R&D costs -6.5 -6.6
Non-statutory staff costs -8.9 -11.7
Energy -37.7 -35.4
Maintenance -39.4 -38.1
Advertising, marketing and entertainment costs -20.6 -23.2
Service, information management and office costs -29.0 -25.5
Exchange rate losses related to foreign exchange derivatives -0.7 -1.1
Other expenses -31.0 -32.6
Total other operating expenses -187.7 -187.5
Audit fees
The Group’s audit fees paid to independent auditors are presented in the table below. The audit fees are in respect of the audit of the annual accounts and legislative functions closely associated therewith. Other expert services include tax consulting and advisory services in corporate arrangements.
2017 2016
Audit fees -0.5 -0.6
Tax consultation -0.0 -0.0
Other fees -0.8 -0.4
Audit fees, total -1.3 -1.0
PricewaterhouseCoopers Oy was paid from non-audit services to entities of HKScan in total 17 thousand euros during the financial year 2017. These services comprised of assurance services 6 thousand euros, tax services 5 thousand euros and other services 6 thousand euros.