How to report the difference between the "prospects status" week after week ?

How to report the difference between the "prospects status" week after week ?

I want to generate a report which shows me which prospects have been changed those last 7 days.

Here is a sample of data : 

Prospect Owner -  Prospect Name - Company   -  Prospect Status (last week) - Prospect Status (current)
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Superman             Batman                Marvel           Not Contacted                        Contacted