The 100km clause is a reason to pin lower. This is a really, really weird definition of "large-scale rioting" that actually is more geared towards the question "will there be a really large riot somewhere in the United States in 2020" than "Will the US see large-scale rioting in 2020".

@dan Important to also note that $1B in 1992 money is $1.8B in 2020 money, per (despite the URL, they're using an updated inflation calculator).

Back-of-the-envelope would have the building total at 880. Obviously cars/police stations/skyscrapers are using current math, per the spreadsheet, and don't have to be adjusted.

@(Tamay) Wow, thanks! My first thought was to go a little bit further and add "single" ("a single massive riot") but I guess it sort of goes down the rabbit hole ("was Occupy a single movement?"). Sometimes the harder one tries to define something the less-clear it ends up being. Would also help to change the description (if that can be done): This question asks: <s>Will the United States experience an incident of large-scale rioting in 2020?</s> _Will the US see a massive riot in 2020?_ For the purposes of this question, <s>'large-scale rioting'</s> ...

@JonathanShi Ah, thank you, that math does seem to put things into better perspective.