To those not that familiar with NetHack, it's possible to run up arbitrarily high scores by doing activities within the game such as pudding farming. This is essentially a risk-free way (when done correctly) to get an unbounded number of kills, and as each kill is worth points, an unbounded score as well. I believe the score maxes out at 2 billion something, i.e. the maximum value of a signed int. So you may as well consider all 7 digit and up scores for ascended characters to belong to one single group, as any of these characters could have arbitrarily inflated their score, they just chose not to, as it's relatively uninteresting/boring to do.

What's more interesting is a low score ascension. That is insanely hard to pull off as it means you're taking a very fragile character into the endgame, and yet somehow pulling through.