WORKAROUND:
The following SQL query should return the needed data by changing the date to suit your needs. As this is a manual SQL query, it is not supported and provided here for informational purposes:
SELECT ServerName AS 'Server Name', Count(*) AS Total FROM Topology.Server WITH(NOLOCK) Inner Join
dbo.AuditEvent_IX_AgentID On Topology.Server.ServerID = dbo.AuditEvent_IX_AgentID.AgentID
WHERE _date_hh BETWEEN '2019-02-01' AND '2019-05-31' AND ServerName like '%' Group By ServerName
STATUS:
Enhancement Request VSTS157022 has been submitted to be considered for a future release of Change Auditor.