You're author's score is going to forever be going up and then down. . . then up and then down.
Don't think about it much. All you should do is think about writing your next hub, and about commenting the other hubs that you like, and also about which other websites you want to share your hubs on.
Yesterday my author score was down to 90 - tomorrow it might be 97. . .or 85. Who cares?
Try to write the best hubs that you can about the things that you know the most about - and eventually you'll win.