Extract numerical data from MS Word graph

Question

I have a word document that includes chart objects linked to data held in unknown spreadsheets that cannot be accessed.

The charts are 'frozen', in the sense that they are displaying the data correctly, despite the data links being effectively severed (although the links themselves DO still exist in File>Info>Related documents>Edit links to files, but the source locations are meaningless on my machine). Accordingly, use the Edit Data command simply confirms that "the linked file is not available".

The numerical data forming each chart series must exist in some form within the Word doc, since if the mouse cursor is hovered over any particular point, the pop-up appears with the x and y data. However, if the graph object is copied into, say, Excel, the chart appears blank as the series then refer to blank cells within the spreadsheet.

QUESTION: How can I automatically extract the numerical data from these charts (i.e. without having to manually read each individual point and write down the values)?