It took me two reads and some additional thinking before I was able to unravel what is shown here. So I try to summarize what is displayed in this chart.

Looking at the Top 100: Here we have Unrated:0 Borked:10% Bronze+:61% Silver+:58% Gold+:51% Platinum:6% Native:29%

Some, but not all of these categories include the ones below. (Not even the rating definition will explain this) So every game that is considered Platinum is additionally counted as Gold+, Silver+, Bronce+, but not as Borked, Unrated or Native. So you have 51% of games that are Gold+ and additionally 29% with Native support, summing up to 80% Gold++.

I feel they guys at /r/dataisbeautifull might be able to create a better visualization of this.