I would like to share with you this article on the Harvard Business Review. They give excellent advice to ‘make extreme numbers resonate’. They give 3 examples to illustrate their tips:
Challenge: Every year tens of thousands of people leave one U.S. city for another. How can you show changes on this scale when it’s so hard to keep track of complex movement? […]
In the first example, they give tips to visualise huge numbers, the second one is for small numbers, but the the third one is really interesting, as it shows an extremely clear way to picture complexity.