Bottom Section
If you select line of subject in the main window, document for which interest have to be calculated are displayed in the bottom section according to the set criteria:

By checking Calculate in the main window, all documents in the bottom section have it checked also. Optionally, you can uncheck them. If you should uncheck all documents in the bottom section, it will be automatically unchecked with the subject displayed in the main window.
Data from documents appear in the bottom section according to the selected tab in document header:
Preparation
Calculation