Why does 1 bad review have such a high impact on my account?

[oysterpancake]

I got a bad review on my account about a year ago, initially it only docked me down to 98% but as the months go by it's down to it's lowest 96% (I understand the decrease is just the fazing out reviews older than a year from my rating.)

My just confusion is...anytime I get a positive review it only takes my rating up 0.2%
Why does 1 review take 4% of my rating, while any positive review is only worth a +0.2% 

I have been actively making sales, and if it weren't for the people giving me positive reviews my account would probably be less than 96% at this point.

[*lady*madonna*]

@oysterpancake

The positive Feedback percentage is calculated based on the total number of positive and negative Feedback ratings for transactions that ended in the last 12 months, excluding repeat feedback from the same member for purchases done within the same calendar week.

Your 12 month Feedback rating: Positives: 25   Negatives: 1

25 / ( 25 + 1 ) = 96.2%