When an internal auditor finds that the incidents of noncompliance exceed the organization's acceptable tolerance level, this should be included in the final engagement report. In this case, the 8 out of 90 desks found with sensitive information represent an 8.9% noncompliance rate, which exceeds the organization's tolerance limit of 4%. Reporting this observation in the final engagement report ensures that management is informed and can take necessary corrective actions to address the noncompliance.
Reference:
IIA Standards: 2410 - Criteria for Communicating
IIA Practice Guide: Reporting and Monitoring