A sketch can work

A graph can be good without being dry and sober.

This one has the character of a rough sketch. Yet it communicates better than plain words and has more emotional resonance than a polished graph would. Even without refinements, we have an expectation of how to read a time series plot that works for this example.

The grapher is Charles Hutton, and he’s a hoot.

Interestingly Charles Hutton is also the name of the man credited with inventing contour plots in 1778.