Hello all. Hopefully someone can help me out here.

Here is my current situation.  I currently have code (in C#) that imports Excel Spreadsheet data into SQL Server using OleDb and the SQLBulkCopy class.  While that works perfectly, the problem is the spreadsheet is updated with new data multiple times daily. Right now, whenever a new Excel spreadsheet is imported I simply delete all of the data that is currently in the database table and repopulate it with the new spreadsheet.  I find this somewhat inefficient, though.  What I would like is for only the new data to be imported and the old data to remain.  Also, I would only like for the newest data to be displayed.  I can easily provide search controls for the user to be able to search for old data, I simply want a way to display the newest data.  I'm not sure if it would require some super-complex SQL query/command or not, but I really don't care what I have to do b/c I have a deadline coming up.  Any help is greatly appreciated. 

 
Thanks,

Josh