Hi Gaurang,
I concur with Mike's comment, retrieive the History for the date range and make sure that there are values for the range, and then execute the Average and Average TW.
You might also want to consider configuring a PCoConnector in Data Servers and using a PCoQuery. Make sure the PCo Agent Instance set up to listen on separate ports for the two MII versions if you want to use separate Data Servers for each.
Regards, Steve