The purchase history page tracks the purchases you've made under a single account. If you believe a transaction is missing, confirm that you didn't use a different email address.
Click the order number (e.g., #ds-0807) in the payment id column to view the details of each purchase. The purchase details page will show you any associated license keys and details of your subscription payments. You can also re-download an app from here if you still have a valid license.
Click on view invoice in the invoices column to access a downloadable PDF of your purchase, which includes detailed tax information.