VLOOKUP - If table array is blank, need it to return blank

All,

I am creating a tracking spreadsheet where i can toggle between months (attached). It returns data properly when I select January or February from the yellow highlighted dropdown list. However, when i choose March, it returns 1/0/1900 because no data has been entered for March (table array) on the AAAG tab. How do I write the formula to return a blank cell on the summary sheet when no information has been entered into the table array yet?

Thanks!