Modules & VBA :: SQL Statement For Append Query?

I have a database where I am pulling my data in my subform from a tbl made by a make table query. However, Once a month the data will be updated and sorted by "Retrieve Date". I have made a function through a module that updates the queries with the latest retrieve date everytime new data is pasted into the database.

I am looking for a way to make the make table query only update the new data and not post records into the tables more than once. Should this be done by writing an IIF then statement and using an append query? I will copy the SQL code from my make table query below.

SQL:

SELECT qrySummary.CounterpartyName, Format([CDSsprd],"Standard") AS CDSspread, Format([Gsprd],"Standard") AS Gspread, Format([RatingsGrade],"Standard") AS RatingGrade, Format([BloombergCDS],"Standard") AS BloomCDS, Format([Avgerage],"Standard") AS [Avg], qrySummary.RetrieveDate INTO tblSummaryQry
FROM qrySummary;