That means that out of the 80% of your reviews for which you are required to achieve 5 stars, you achieved 77%.
So 80% is the targeted requirement and the 77% is what you actually achieved of the targeted requirement.
In simplified terms, you are not required to get 5 stars for 100% of you bookings just for 80% of your bookings and out of 80% of your bookings, you achieved 77% of 5 stars.
I have different figures as well, everybody will have 80% as the primary figure because that is a fixed target but our actual achieved rates will differ depending on the stars we received.