Reduce "Special" trait probability by 50% each new tier

There are currently 572 Solos with one of the 38 "Special" traits. That means that around 22% of existing Solos have one of these traits.

In comparison, there are only 7 Solos with a "Saturnalia" trait (<0.3%).

Individually, we find that the rarity of the "Portrait" trait (0.27%-1%) is often higher than that of the individual "Special" traits (0.27%-0.87%).

I propose that each time the "Step Function" is activated, the probability of a "Special " trait appearing is reduced by 50%. This would get activated when we reach 5000 Solos, which gives ample time to the community to generate Solos with a higher "Special" probability.

By reducing the probability, we can estimate that total "Special" Solos will amount will be reduced to a total of around 2000, down to 10% (from 22%) and effectively becoming rarer, on average, that individual "Portrait" traits.