Planet availability, strangeness

I started game with all five AI's, all at average, mix of 1 good, 1 evil, 3 neutral, Gigantic galaxy, planets set to common. I came across 20 class planets on a regular basis (hard to say exactly how often, but more than I've been use to). Game sucked in the way it was shapping up (another issue) so started a new one.

This time only three AI's, 1 good, 1 evil, 1 neutral, all other settings the same. Only now, I'm hardpressed to find a 13 or 14 class planet to colonize. :notsure: puzzling...