Count of API calls (On-Premise)

Good afternoon

My company wants to migrate to the cloud version of CRM. One of the tasks before me is counting the number of API calls in the current system.

Now our system has 20 Win services 10 Web services and it has a lot of different logic. (C#)

How can I count the number of requests to OrganizationService in a minute/hour/day?

I would not want to resort to logging each such step