I think it might be interesting and valuable to create a "list of numbers every EA should know", in a similar vein to Latency Numbers Every Programmer Should Know and Key Numbers for Cell Biologists.
I was originally thinking of either a) making the whole list myself, or b) convincing someone else (eg, an RP intern) to do it, but on AaronGertler's advice I decided to turn to the Forum to help with crowdsourcing this problem.
We can use upvotes/downvotes and comments to debate which numbers should be worth including/excluding.
So what are some key numbers that (almost) every EA should know?
Feel free to answer with either important numbers that you think are cause-specific (eg, numbers of chickens currently alive in factory farms, Toby Ord's x-risk estimates, extreme poverty rates in 1950 vs 2018) or relatively cause agnostic (eg, $billions that Open Phil has, expected lifespan of social movements, number of atoms in the observable universe).
I think that's about right in the US, ~50 billion worldwide, but ~20 billion alive at any moment worldwide.
https://www.weforum.org/agenda/2019/02/chart-of-the-day-this-is-how-many-animals-we-eat-each-year/