Cummulative

I'm having trouble creating a cummulative column in a table.

I've got the following table, sorted ASC PAID

Claim_Number Paid
123 $21.22
124 $34,87
456 $42.90
478 $67.00
890 $100.10

I want to add a column (in a new table) with the cummulative total paid. It should look like

Claim_Number Paid Cummulative
123 $21.00 $21.00
124 $34.00 $55.00
456 $42.00 $97.00
478 $67.00 $164.00
890 $100.00 $264.00


Thanks for the help.

Ray