Reports > Sales/Shopping Cart/Products/Customers etc.
In admin, you can also extract a series of reports, for example bestsellers, monthly sales, tax, etcetera. You can extract all of these reports as csv or xml-files. You can determine the period of extracting the reports yourself. You can even choose what status the orders that are included in the report should have.
Below you can see how it might look like if you were to extract a report on orders over a certain period.