That looked like a lot of work, to be honest most of it really did not make a lot of sense to me, until I read the comments. I think like a few of the comments suggest, is that they vote for who they know, who they have seen. Me I get quite a few votes from a few people in the mid 60's rep range, and from a couple in the low 70's range, I also end to give them my biggest votes, and spread the rest of my vote power out among new users.
I am I guess what would be called a content fan. Some content I just love, like the fiction writers, several authors I show my support to by my vote, but I have also as time passed and my priorities have changed/grown, now spend time helping out new users, to see what their content is going to be, I have found new writers, and new philosophy writers/thinkers, and even some really cool photographers. As steemit is growing I want to help it, and as the content grows I feel I do also.
I think when you re-run this analysis in 3 to 6 months time, that you will start to see a gradual spreading of votes through all the levels. But during the next 3-6 months those of us in the 45-65 range today, will be higher rep levels. I'd like to think that the majority of my voting will still be toward new user, and new content they bring, but thoughts and likes and dislikes change with growth and time. But very nice job.