It's an analogy to explain the point.

I'm saying the ranked list of people by power, random* MPs are in the 99th percentile.

I mean, is there even a single politician in the world who represents less than 99 people? (There used to be**, but any current examples?)

* OK, so that doesn't work over literally all polities — a Tuvalu MP might not have as much power as the parking attendant nearest to the Australian parliament building — but hopefully this at least helps clarify? Perhaps?

** https://en.wikipedia.org/wiki/Rotten_and_pocket_boroughs