You can set the time to Feedback request. The default has been 8 weeks as far back as I can remember. This also means that you can estimate which ads/products/services are responsible for spikes and dips.
I had lots of issues with Feedback before having a score of 1.1 at one time. I used the time to feedback to identify two ads that were causing the massive score drops.
As a side not: The problematic ads turned out to be 2 of my top selling products with highest ROAS, lowest CPMs and other fantastic metrics.