The XML files can be opened easily using Microsoft Excel 2003. A simple approach is to start Excel and either use the File Open menu or to drag the file on to a blank Worksheet. In either case the following dialogue box will appear:
You can then select "As an XML list" and a further query will appear:

It is possible to choose OK so that Excel will create a schema based on the XML source data.
Data will appear in columns in the Excel spreadsheet and can be plotted and manipulated using the standard Excel functions. The Worksheet will look something like this:

