Try setting up an automation that'll run a day before you do the imports, and give it a 'Find Record' action to grab all the records you have now. In the screenshot below I did it with 'Where name is not empty', but you could do this with any condition that makes sense for your business or with a view instead
Then, use a repeating group on that list and for each of the found records paste 'This Week's Apples' value into 'Last Week's Apples'

And I've set it up for you here!