Calculating percentage change of a cell that updates on refresh

I understand you can calculate percentage change by using, for example, =(A1/A2)-1 where A1 is the first months income and A2 is the second months income -

On my spreadsheet however I have a cell that takes data from an online currency site which I manually refresh. Is there any way I can have a cell that will calculate the percentage change upon refresh? For example if the cell was $60 and then updated to $95 when refreshed, another cell would be populated with 58.33%?

Originally Posted by Special-K

If your sheet takes data from the online currency site using VBA then just modify the VBA to produce a history (even if it's just old value and new value) of the previous values which will allow you to calculate the percentage change.

It doesn't unfortunately, I'm importing the data using the Web Query / Data ->From Web function to another sheet and then importing the relevant cell from that sheet