Imagine a Martian trying to make sense of this world and the only available data are the Summer Olympic medal tables from the past century.
How much would that explain? Quite a lot, it turns out. In fact, it would be challenging to find anything else so concise that says so much about the past century as the tables below.
The four bar charts show the countries that usually win the largest share of medals — the United States, China, Russia and Germany — and how they have performed since 1912.