By clicking on any of the four datasheet links on the Home Page, you will see an Excel spreadsheet, which will have been saved to the default folder on your hard drive.*
You can save the spreadsheet to another folder, if you require. You can also make changes to the spreadsheet, to manipulate and analyse the data, and save your changes.
If you have made changes to the data and want to return to the original version of the spreadsheet, close your current copy and click on the datasheet link on the Home Page again to re-launch the original version.
*In some cases the operation of a pop-up blocker may prevent the spreadsheets opening. If this is the case, click on the spreadsheet links while holding down the CTRL-key. This should temporarily override the blocker.