So the most number of humans in space is 11, which has happened a number of times.

Most number of humans in space is 13 according the graph in the link. You must be looking at second graph, most numbers of Americans in space at a time is 11.

Most number of Americans in space is actually 10 according to second graph :)

looks like 13, at least according to the arcaneknowledge link

so it looks like on average it's roughly doubling about every 15 years?

The xkcd graph is kind of sad.

> world

[Gumble, grumble, …] I think the Earth, the Moon, and the rest of the universe count as the same world.