Report Question - CRM Report ID vs ReportServer ReportID?

Hi, I have a general question on CRM Reports. I was trying to find the Reports LastUsed information by using the following Query.

SELECT  Distinct    UserName, TimeStart, TimeEnd, Source, Status
FROM         [ReportServer].[dbo].[ExecutionLog] ReportServerLog INNER JOIN
[MYCRMDB].[dbo].FilteredReport CRMReports ON CRMReports.reportid = ReportServerLog.ReportID

The query always returned 0 results.

After doing some research, I found that the ReportID logged into the ExecutionLogStaoragetable in ReportServer is different from the ReportID from the CRM Reports table. But I notice that, running the same report logs the same ID. 

What the the mapping between CRM ReportID to the ReportServer ReportID? Can someone please advise.

Thanks.