How can I write a query in Microsoft Access that references the row above it?

Specifically, I have a table that looks like this:
Row 1: 7
Row 2: 1
Row 3: -3
Row 4: -6
Row 5: -2
Row 6: 9
Row 7: 10

I want to write a query that will calculate a running total, but will never go negative. So the results would be:
Row 1: 7
Row 2: 8
Row 3: 5
Row 4: 0
Row 5: 0
Row 6: 9
Row 7: 19