4.3.34Independent Auditor’s Fees and Services

Fees included in other operating costs related to PwC, the 2018 and 2017 Company’s external independent auditor, are summarized as follows:

in thousands of US$

2018

2017

Audit of financial statements

2,209

1,861

Out of which:

- invoiced by PwC Accountants N.V.

1,133

1,009

- invoiced by PwC network firms

1,076

852

Tax advisory services by PwC network firms

79

47

Other non-audit services

111

101

Total

2,399

2,009

In both 2018 and 2017, the other non-audit services were mainly related to the review of the Company sustainability report.