1) Go to Business and Orders will be the default landing section.
2) Go down the page to the Completed orders section.

3) Click the plus symbol to expand the Completed Orders section.

4) Click "Downlaod CSV Data File of all Completed Orders"

NOTE: Depending on your chosen spreadsheet application, the following steps and/or accompanying images may vary.

5) Save the CSV file in Excel or your chosen spreadsheet application.

6) When you open the file, it may ask you how you want to the data to be seperated into columns. Choose Comma.
7) Once open, you should be able to manipulate the data as needed such as filter by the date column to ensure you are only using data from the applicable financial year and add a summing row to the bottom of the data columns to get totals for each of the numeric columns.